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Background: Persistent cognitive impairment is a serious consequence of the post-COVID condition. However, there have been no established effective treatments for this pathophysiology supported by sufficient evidence., Case Presentation: A 32-year-old woman became aware of difficulty in word recalling, reading, and writing as well as difficulty in completing various household multitasks 3 weeks after the COVID-19 infection. Although blood tests, magnetic resonance imaging, electroencephalography, and Kohs block design test were all within normal limits, completion time by trail making test (TMT) A or B was markedly delayed. Finally, she was referred to our hospital 3 months after the infection. At baseline, the THINC integrated tool (THINC-it), a digital battery consisting of the five-item version of the perceived deficit questionnaire (PDQ-5), choice reaction time (CRT), 1-back test, digit symbol substitution test (DSST), and TMT-B, revealed poor capability in attention, working memory, and executive function. Also, near-infrared spectroscopy (NIRS) demonstrated no activation in frontal or temporal regions during verbal fluency task. Extended-release guanfacine (GXR) 2 mg/day was initiated and a month later was elevated up to 4 mg/day as a maintenance dose. The PDQ-5, CRT, 1-back test, DSST, and TMT-B were dramatically improved 1 month after GXR treatment. NIRS finding was also normalized after 2 months of treatment. These effects were successfully maintained throughout the 6-month follow-up period., Conclusion: GXR may be helpful in improving subjective/objective cognitive functioning and frontotemporal brain activity in long-COVID patients manifesting apparent cognitive impairment., (© 2024 The Author(s). Neuropsychopharmacology Reports published by John Wiley & Sons Australia, Ltd on behalf of The Japanese Society of Neuropsychopharmacology.)

Background: This study examined the cutaneous analgesic effects of lidocaine co-injected with guanfacine and its comparison with dexmedetomidine., Methods: Cutaneous analgesic effects are quantified through the blocking effects of the cutaneous trunci muscle reflex against skin pinpricks in rats. The dose-response curves of guanfacine, dexmedetomidine, and lidocaine were constructed and drug-drug interactions were analyzed by the ED 50 isobologram., Results: Subcutaneous injections of guanfacine, dexmedetomidine, and lidocaine produced dose-dependently nociceptive/sensory blockade. On the ED 50 (50% effective dose) basis, the potency rankings of the drug are dexmedetomidine (0.09 [0.08-0.11] μmol/kg) > guanfacine (3.98 [2.96-5.34] μmol/kg) > lidocaine (25.40 [23.51-27.44] μmol/kg) ( p  < 0.01). On their equipotent doses (ED 25 , ED 50 , and ED 75 ), the duration of sensory blockade induced by guanfacine or dexmedetomidine was longer than lidocaine's ( p  < 0.01). Both guanfacine and dexmedetomidine showed synergistic effects with lidocaine., Conclusions: We showed that guanfacine elicits dose-dependent cutaneous analgesia when administered subcutaneously. Lidocaine is less potent than guanfacine or dexmedetomidine. Both guanfacine and dexmedetomidine enhance the potency and duration of lidocaine. Better synergistic responses we are getting with guanfacine plus lidocaine.

Attention-deficit/hyperactivity disorder (ADHD) is characterized by age-inappropriate and impairing levels of inattention, hyperactivity, or impulsivity, or a combination of these characteristics. It is estimated to affect around 4% of adults worldwide. In the past few decades, prescriptions for ADHD drugs (psychostimulants and non-psychostimulants) have increased significantly. However, the efficacy and safety of adult ADHD medications remains controversial. Guanfacine extended-release (GXR) is a non-psychostimulant ADHD drug that is a selective α2A-adrenergic receptor agonist, first approved for treatment of adult ADHD in Japan in June 2019. Our aim was to provide an overview of GXR pharmacology and review the studies on efficacy and safety that have been conducted in adults with ADHD. The beneficial actions of guanfacine are thought to be attributed to the strengthening of prefrontal cortical network connections, which regulate attention, emotion, and behavior via the activity at post-synaptic α2A receptors. Current evidence of GXR efficacy and safety suggests that GXR is an effective monotherapy treatment option for adults with ADHD., Competing Interests: The authors declare that they have no conflicts of interest., (© 2021 Ota et al.)

It has been established that the selective α2A adrenoceptor agonist guanfacine reduces hyperactivity and improves cognitive impairment in patients with attention-deficit/hyperactivity disorder (ADHD). The major mechanisms of guanfacine are considered to involve the activation of the postsynaptic α2A adrenoceptor of glutamatergic pyramidal neurons in the frontal cortex, but the effects of chronic guanfacine administration on catecholaminergic and glutamatergic transmissions associated with the orbitofrontal cortex (OFC) are yet to be clarified. The actions of guanfacine on catecholaminergic transmission, the effects of acutely local and systemically chronic (for 7 days) administrations of guanfacine on catecholamine release in pathways from the locus coeruleus (LC) to OFC, the ventral tegmental area (VTA) and reticular thalamic-nucleus (RTN), from VTA to OFC, from RTN to the mediodorsal thalamic-nucleus (MDTN), and from MDTN to OFC were determined using multi-probe microdialysis with ultra-high performance liquid chromatography. Additionally, the effects of chronic guanfacine administration on the expression of the α2A adrenoceptor in the plasma membrane fraction of OFC, VTA and LC were examined using a capillary immunoblotting system. The acute local administration of therapeutically relevant concentrations of guanfacine into the LC decreased norepinephrine release in the OFC, VTA and RTN without affecting dopamine release in the OFC. Systemically, chronic administration of therapeutically relevant doses of guanfacine for 14 days increased the basal release of norepinephrine in the OFC, VTA, RTN, and dopamine release in the OFC via the downregulation of the α2A adrenoceptor in the LC, OFC and VTA. Furthermore, systemically, chronic guanfacine administration did not affect intrathalamic GABAergic transmission, but it phasically enhanced thalamocortical glutamatergic transmission. The present study demonstrated the dual actions of guanfacine on catecholaminergic transmission-acute attenuation of noradrenergic transmission and chronic enhancement of noradrenergic transmission and thalamocortical glutamatergic transmission. These dual actions of guanfacine probably contribute to the clinical effects of guanfacine against ADHD.

Aim: To assess the empirical evidence for the treatment of attention deficit/hyperactivity disorder (ADHD) in populations with autism spectrum disorder (ASD)., Methods: A systemic PubMed, PsychINFO, Embase, and Medline database search of peer-reviewed literature was conducted. Included in the review were controlled trials published in English with sample sizes ⩾10 participants examining the safety and efficacy of anti-ADHD medication in ASD populations. Data was extracted on relevant variables of study design, demographics, associated psychopathology, medication dose, efficacy, and tolerability., Results: Nine controlled trials met the inclusion and exclusion criteria: five with methylphenidate, three with atomoxetine, and one with guanfacine. Sample sizes ranged from 10 to 128 with 430 children participating across all the trials. In all the trials, treatment response was significantly superior to placebo. However, almost all trials assessed only hyperactivity, and most included only participants with intellectual disability with high levels of irritability. None of the trials distinguished agitation from hyperactivity. The response on hyperactivity for methylphenidate and atomoxetine was less than that observed in the neurotypical population; however, the response for guanfacine surpassed results observed in neurotypical populations. Treatment-emergent mood lability (i.e. mood dysregulation and mood-related adverse events) was frequently associated with methylphenidate and guanfacine treatments. Worse treatment outcomes were associated with individuals with lower intellectual capability compared with those with higher IQs., Conclusions: here is a scarcity of controlled trials examining ADHD treatments in ASD populations, particularly in intellectually capable individuals with ASD and in adults. Response to ADHD medications in ASD were adversely moderated by the presence of intellectual disability and mood lability.

Aim: Previously, we reported on the efficacy and safety of guanfacine extended-release (GXR) in Japanese adults with attention-deficit/hyperactivity disorder (ADHD) from a phase 3, double-blind, placebo-controlled, randomized trial. In this exploratory post hoc analysis, we assessed the efficacy and/or safety of GXR in the following subgroups: ADHD-combined (ADHD-C) and ADHD-predominantly inattentive (ADHD-I) subtypes, age (≥31, <31 years), sex (male, female), and body weight (≥50, <50 kg)., Methods: The primary efficacy endpoint was change from baseline in the Japanese version of the investigator-rated ADHD-Rating Scale-IV (ADHD-RS-IV) with adult prompts (total scores) at week 10., Results: The efficacy analysis population included 200 patients (GXR, 100; placebo, 100). ADHD-RS-IV total score effect sizes (GXR vs placebo) were similar across all subgroups (total population: 0.52, ADHD-C: 0.51, ADHD-I: 0.52, ≥31 years: 0.61, <31 years: 0.47, male: 0.50, female: 0.57). There were no major differences in the incidence/types of treatment-emergent adverse events (TEAEs) across the subgroups. The incidence of significant TEAEs (34.3%, 10.6%) and TEAEs leading to discontinuation (34.3%, 12.1%) were approximately three times higher in females than males, respectively. The incidence of TEAEs in patients weighing <50 kg and ≥50 kg was 100% and 73.6% during dose optimization and 40% and 24.4% during the maintenance period, respectively., Conclusion: Findings from this post hoc analysis in adults with ADHD support the efficacy and safety of GXR regardless of ADHD subtype, age, or sex and suggest that careful monitoring for TEAEs and GXR dose optimization is considered for all patients, as needed., (© 2020 The Authors. Neuropsychopharmacology Reports published by John Wiley & Sons Australia, Ltd on behalf of the Japanese Society of NeuropsychoPharmacology.)

Although norepinephrine (NE) does not appear to play a prominent role in mediating the abuse-related effects of cocaine, studies have indicated that NE α -2 receptor agonists can attenuate reinstatement of extinguished cocaine self-administration in rats and monkeys and can decrease cocaine craving in humans. In the present studies, we examined the effects of two α -2 receptor agonists, lofexidine and guanfacine, on choice between food and cocaine (0.0-0.1 mg/kg per injection) in cynomolgus monkeys. Male and female subjects were housed in stable same-sex social groups of four; social rank did not influence the effects of lofexidine and guanfacine. When administered acutely, lofexidine (0.03-3.0 mg/kg, i.v.) significantly decreased cocaine choice in females ( n = 7) but not males ( n = 8). However, in males, the same lofexidine doses produced dose-dependent decreases in core body temperature ( n = 7), and acute guanfacine (0.003-1.0 mg/kg, i.v.) significantly decreased cocaine choice ( n = 11). When lofexidine was administered for five consecutive days to a subset of the monkeys in whom lofexidine acutely decreased cocaine choice, tolerance to this effect developed to varying degrees of completeness in three of three males and two of four females. Taken together, these data suggest that α -2 receptor agonists can produce small decreases in the reinforcing strength of cocaine relative to food and that, even when efficacy is observed after acute administration, tolerance to the decreases in cocaine choice are apparent and more likely in males compared with females. SIGNIFICANCE STATEMENT: Cocaine use disorder remains a significant public health problem with no US Food and Drug Administration-approved treatments. Although cocaine elevates dopamine, serotonin, and norepinephrine (NE), the latter target has received less research. The present study noted modest effects of NE agonists on the relative reinforcing strength of cocaine with greater efficacy in female compared with male monkeys., (Copyright © 2020 by The American Society for Pharmacology and Experimental Therapeutics.)

Noncompetitive N-methyl-D-aspartate/glutamate receptor (NMDAR) antagonists contribute to the pathophysiology of schizophrenia and mood disorders but improve monoaminergic antidepressant-resistant mood disorder and suicidal ideation. The mechanisms of the double-edged sword clinical action of NMDAR antagonists remained to be clarified. The present study determined the interaction between the NMDAR antagonist (MK801), α1 adrenoceptor antagonist (prazosin), and α2A adrenoceptor agonist (guanfacine) on mesocortical and mesothalamic catecholaminergic transmission, and thalamocortical glutamatergic transmission using multiprobe microdialysis. The inhibition of NMDAR in the locus coeruleus (LC) by local MK801 administration enhanced both the mesocortical noradrenergic and catecholaminergic coreleasing (norepinephrine and dopamine) transmissions. The mesothalamic noradrenergic transmission was also enhanced by local MK801 administration in the LC. These mesocortical and mesothalamic transmissions were activated by intra-LC disinhibition of transmission of γ-aminobutyric acid (GABA) via NMDAR inhibition. Contrastingly, activated mesothalamic noradrenergic transmission by MK801 enhanced intrathalamic GABAergic inhibition via the α1 adrenoceptor, resulting in the suppression of thalamocortical glutamatergic transmission. The thalamocortical glutamatergic terminal stimulated the presynaptically mesocortical catecholaminergic coreleasing terminal in the superficial cortical layers, but did not have contact with the mesocortical selective noradrenergic terminal (which projected terminals to deeper cortical layers). Furthermore, the α2A adrenoceptor suppressed the mesocortical and mesothalamic noradrenergic transmissions somatodendritically in the LC and presynaptically/somatodendritically in the reticular thalamic nucleus (RTN). These discrepancies between the noradrenergic and catecholaminergic transmissions in the mesocortical and mesothalamic pathways probably constitute the double-edged sword clinical action of noncompetitive NMDAR antagonists.

Objective: To assess guanfacine extended-release (GXR) efficacy and safety in adults with attention-deficit/hyperactivity disorder (ADHD)., Methods: This phase 3, double-blind, placebo-controlled study (conducted between October 2016 and July 2017) included Japanese patients aged ≥ 18 years with ADHD (DSM-5). Patients received GXR (n = 101) or placebo (n = 100) titrated from 2 mg/d to 4-6 mg/d (dose-optimization; 5 weeks), followed by 4-6 mg/d (dose-maintenance; 5 weeks), then tapered doses to 2 mg/d (2 weeks). Primary endpoint was change from baseline in total score on the Japanese version of the ADHD-Rating Scale IV with adult prompts (ADHD-RS-IV) at week 10. Other measures were ADHD-RS-IV subscales, Clinical Global Impression-Improvement scale (CGI-I) and Patient Global Impression-Improvement scale (PGI-I) (percentage of patients very much improved/much improved), treatment-emergent adverse event (TEAE) incidences, and TEAEs leading to discontinuation., Results: Compared with placebo, there was statistically significantly greater improvement in ADHD-RS-IV total score reduction with GXR (least squares mean ± SE: GXR vs placebo, -11.55 ± 1.10 vs -7.27 ± 1.07; P = .0005; effect size 0.52). There were significantly greater improvements in GXR for ADHD-RS-IV inattention (-7.39 ± 0.79 vs -4.89 ± 0.76; P = .0032) and hyperactivity-impulsivity (-3.84 ± 0.54 vs -2.10 ± 0.52; P = .0021) subscale scores, CGI-I scores (48.1% vs 22.6%; P = .0007), and PGI-I scores (25.3% vs 11.8%; P = .0283). More patients in the GXR versus the placebo group reported TEAEs (81.2% vs 62.0%) and discontinued due to TEAEs (19.8% vs 3.0%). The main TEAEs in the GXR group were somnolence, thirst, blood pressure decrease, nasopharyngitis, postural dizziness, and constipation; most TEAEs were mild to moderate in severity., Conclusions: In Japanese adults with ADHD, GXR improved ADHD symptoms without any major safety concerns., Trial Registration: Japan Primary Registries Network (https://rctportal.niph.go.jp/en): JapicCTI-163231, (© Copyright 2020 Physicians Postgraduate Press, Inc.)

Introduction : Attention-deficit/hyperactivity disorder (ADHD) commonly occurs in children, adolescents, and adults. Although symptoms of ADHD often respond robustly to treatment with stimulants (amphetamine or methylphenidate), not all patients are appropriate candidates for treatment with these drugs. Guanfacine extended-release (GXR) is a non-stimulant alternative drug approved for the treatment of ADHD in the United States (U.S.), Canada, and Europe. Areas covered : The chemistry, pharmacokinetics, mechanism of action and dosage of GXR are presented. Efficacy and safety data obtained in clinical trials with subjects aged 6-17 years for both GXR monotherapy and use in combination with stimulants are described. Meta-analyses comparing GXR to other drugs are presented. MedWatch surveillance data collected for GXR since approval in the U.S. are also discussed. Expert opinion : Although GXR is effective for the treatment of ADHD and has a different side effect profile than stimulants, it is not as impressive in reducing symptoms. Despite the availability of multiple pharmacological treatments for ADHD, there remains an unmet need for formulations as potent as stimulants but with fewer adverse effects. Several pharmacological agents for ADHD treatment are in development. It is not clear that any of these compounds will replace currently available formulations as first-line alternatives.

Objective: To assess treatment patterns, health care resource utilization, and health care costs associated with use of atypical antipsychotics (AAPs) or the nonstimulant guanfacine extended release (GXR) after stimulant therapy for attention-deficit/hyperactivity disorder (ADHD). In Canada, GXR is approved as a monotherapy for children and adolescents with ADHD or as an adjunct to stimulants, and AAPs are commonly used off-label as an adjunct to stimulants. Methods: Health care claims data (January 1, 2007 to March 31, 2016) from Quebec's provincial health plan were assessed for individuals with ADHD, 6-17 years of age, who received ≥1 stimulant followed by a first AAP or GXR prescription (index medication), without a diagnosis for which AAPs are indicated. Results: Overall, 1327 individuals were included (AAPs, 1098; GXR, 229). Rates of discontinuation, augmentation, or switching of the index medication did not differ between AAPs and GXR during the first follow-up year. Discontinuation rates were significantly lower with GXR than with AAPs during the second year (22.0% vs. 35.9%; p  = 0.03). GXR and AAPs resulted in similar increases in total health care cost. In GXR users, the increase in prescription drug cost after 6 months was higher than in AAP users, whereas the increase in overall medical cost was higher with AAPs than GXR, owing to more psychiatric department visits. Conclusions: In children and adolescents with ADHD who used AAPs or GXR after stimulants, secondary treatment changes were similar with both treatments after 1 year, but discontinuation rates were significantly lower with GXR than with AAPs in the second year. The greater increase in prescription cost with GXR was balanced by a greater increase in overall medical costs with AAPs, resulting in no overall difference in total health care cost between the two treatments.

The selective α2A adrenoceptor agonist guanfacine reduces hyperactivity and improves cognitive impairment in patients with attention-deficit/hyperactivity disorder (ADHD). The major mechanisms of guanfacine have been considered to involve activation of postsynaptic α2A adrenoceptor in frontal pyramidal neurons. However, the effects of chronic guanfacine administration on catecholaminergic transmissions associated with the orbitofrontal cortex (OFC) remain unclear. To explore the mechanisms of action of guanfacine on catecholaminergic transmission, the effects of its acute local or sub-chronic systemic administration on catecholamine release within pathways from locus coeruleus (LC) to OFC and reticular thalamic nucleus (RTN), from RTN to mediodorsal thalamic nucleus (MDTN), and from MDTN to OFC were determined using multi-probe microdialysis with ultra-high performance liquid chromatography. Acute OFC local administration of guanfacine did not affect catecholamine release in OFC. Acute LC local and sub-chronic systemic administrations of guanfacine reduced norepinephrine release in LC, OFC and RTN, and also reduced GABA release in MDTN, whereas AMPA-induced (perfusion with AMPA into NDTN) releases of l-glutamate, norepinephrine and dopamine in OFC were enhanced by sub-chronic systemic guanfacine administration. This study identified that catecholaminergic transmission is composed of three pathways: direct noradrenergic and co-releasing catecholaminergic LC-OFC pathways and intermediate LC-OFC (LC-RTN-MDTN-OFC) pathway. We demonstrated the dual actions of guanfacine on catecholaminergic transmission: attenuation of direct noradrenergic LC-OFC transmission at the resting stage and enhancement of direct co-releasing catecholaminergic LC-OFC transmission via GABAergic disinhibition in the intermediate LC-OFC pathway. These dual actions of guanfacine probably contribute to clinical actions of guanfacine against ADHD and its comorbid symptoms. This article is part of the Special Issue entitled 'Current status of the neurobiology of aggression and impulsivity'., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Guanfacine is used for the treatment of attention-deficit/hyperactivity disorder (ADHD). Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), metabolite profiling of guanfacine was performed in plasma and urine collected from healthy Japanese adults following repeated oral administration of guanfacine extended-release formulation. Unchanged guanfacine was the most abundant component in both plasma and urine (from the MS signal intensity). In plasma, the M3 metabolite (a sulfate of hydroxy-guanfacine) was the prominent metabolite; the M2 metabolite (a glucuronide of a metabolite formed by monooxidation of guanfacine), 3-hydroxyguanfacine and several types of glucuronide at different positions on guanfacine were also detected. In urine, the M2 metabolite and 3-hydroxyguanfacine were the principal metabolites. From metabolite analysis, the proposed main metabolic pathway of guanfacine is monooxidation on the dichlorobenzyl moiety, followed by glucuronidation or sulfation. A minor pathway is glucuronidation at different positions on guanfacine. As the prominent metabolites in plasma were glucuronide and sulfate of hydroxyguanfacine, which have no associated toxicity concerns, further toxicity studies of the metabolites, for example in animals, were not deemed necessary., (© 2019 The Authors. Biopharmaceutics & Drug Disposition published by John Wiley & Sons Ltd.)

Objectives: To assess the impact of long-term pharmacotherapy with guanfacine immediate- or extended-release (GXR), administered alone or as an adjunctive to a stimulant, on weight and height in children and adolescents with attention-deficit/hyperactivity disorder (ADHD). Methods: Data were extracted from U.S. Department of Defense medical records for patients 4-17 years of age at index date (initiation of any study medication following a year without ADHD medications, or diagnosis if unmedicated) with weight/height measurements for the analysis period (January 2009-June 2013) and the previous year (baseline). Longitudinal weight and height z -scores were analyzed using multivariable regression in three cohorts: guanfacine (initial period of guanfacine exposure), first-line stimulant monotherapy (initial period of exposure), and unmedicated. Guanfacine cohort subgroups were based on previous/concurrent stimulant exposure. Results: The weight analyses included 47,910 patients (66.8% male) and the height analyses 41,248 (67.2% male). Mean initial exposure in the weight analyses was 237 days (standard deviation [SD] = 258, median = 142) for guanfacine and 257 days (SD = 284, median = 151) for first-line stimulant monotherapy, and was similar in the height analyses. Modeling indicated that guanfacine monotherapy was not associated with clinically meaningful deviations from normal z -score trajectories for weight (first-line, n  = 943; nonfirst-line, n  = 796) or height (first-line, n  = 741; nonfirst-line, n  = 644). In patients receiving guanfacine adjunctive to a stimulant, modeled weight ( n  = 1657) and height ( n  = 1343) z -scores followed declining trajectories. In this subgroup, mean standardized weight/height had decreased during previous stimulant monotherapy. For first-line stimulant monotherapy, modeled weight ( n  = 32,999) and height ( n  = 28,470) z -scores followed declining trajectories during year 1. In the unmedicated cohort, modeled weight ( n  = 11,515) and height ( n  = 10,050) z -scores were stable. Conclusions: Guanfacine monotherapy (first-line or nonfirst-line) was not associated with marked deviations from normal growth in this modeling study of children and adolescents with ADHD. In contrast, growth trajectories followed an initially declining course with stimulants, whether given alone or with adjunctive guanfacine.

Objective: To examine the role of Guanfacine Extended Release (GXR) in the management of behavioral disturbances in patients with Prader-Willi Syndrome (PWS). Methods: Twenty from a total of 27 individuals with genetically confirmed PWS, 6-26 years of age, with the following symptoms were identified: significant aggression/agitation, skin picking, and/or symptoms of attention-deficit/hyperactivity disorder (ADHD). Response to GXR for the above noted symptoms was categorized as improved, worsened, or unchanged, while assessing for side effects and tolerability. Results: Eleven of the 20 individuals reported skin-picking, 17 reported aggression/agitation, and 16 reported symptoms of ADHD. Nine (81.8%), 14 (82.3%), and 15 (93.7%) individuals showed an improvement in skin-picking, aggression/agitation, and ADHD, respectively, while on GXR treatment. Two patients with prior complaints of psychotic symptoms did not respond to GXR. Of note, no abnormal weight gain or significant adverse reaction was observed in this group, while on GXR. Conclusions: In this study, GXR demonstrated improvement in symptoms of skin picking, aggression/agitation, and ADHD in patients with PWS. GXR was not effective in reducing psychosis or agitation related to psychotic symptoms. Future studies are warranted to further establish the utility of GXR in PWS patients.

Background: Guanfacine is Food and Drug Administration approved for hypertension and attention-deficit hyperactivity disorder and has been used off-label for migraine prophylaxis, heroin withdrawal, and more recently smoking cessation. Previous studies have shown positive effects of 3 mg/d of immediate-release (IR) guanfacine on smoking outcomes, but the dose equivalency of the IR and extended-release (ER) formulations is unknown., Procedures: A within-subject design was used to compare the pharmacokinetics and pharmacodynamics of 3 mg/d of IR, 4 mg/d of ER, and 6 mg/d of ER guanfacine in adult daily smokers (n = 5). Plasma medication levels, vital signs, cigarettes per day, tobacco craving, and adverse events were assessed. Medication was titrated to stable dosing after each laboratory day (3 mg/d IR, then 4 mg/d ER, then 6 mg/d ER)., Results: Plasma medication levels did not differ between the 3 mg/d of IR and 4 mg/d of ER doses after 24 hours from last dose and were highest at the 6 mg/d of ER dose (3 mg/d IR: M = 3.40 ng/mL, SE = 0.34 vs 4 mg/d ER: M = 3.46 ng/mL, SE = 0.67 vs 6 mg/d ER: M = 5.92 ng/mL, SE = 1.02). All doses of guanfacine decreased heart rate and blood pressure from baseline. Absolute values of cigarettes per day (6 mg/d ER) and tobacco craving (4 and 6 mg/d ER) were lowest with the ER formulations. Treatment-emergent adverse events were subject rated as minimal to mild, except dry mouth., Conclusions: We demonstrated similar pharmacokinetic profiles between 3 mg/d of IR guanfacine and 4 mg/d of ER guanfacine, as hypothesized. All doses of guanfacine were well tolerated.

This article is the first reported case describing the off-label use of enteral immediate-release guanfacine, a long-acting α-2 adrenergic agonist most commonly used in the treatment of attention-deficit hyperactivity disorder, for sedation in a patient with severe anxiety and agitation limiting mechanical ventilation weaning several days after cardiac surgery. In this case, after several days of unsuccessful attempts to control his agitation and anxiety with conventional therapies, guanfacine therapy was initiated, and the patient was rapidly weaned from all other sedatives and mechanical ventilation shortly thereafter. The patient was weaned from guanfacine therapy without evidence of bradycardia, hypotension, or rebound syndrome. Enteral guanfacine therapy should be further studied as a potentially useful and cost-effective sedative therapy for patients with severe anxiety and/or agitation in the intensive care unit following cardiac and thoracic surgical procedures.

Stress is a precipitating agent in neuropsychiatric disease and initiates relapse to drug-seeking behavior in addicted patients. Targeting the stress system in protracted abstinence from drugs of abuse with anxiolytics may be an effective treatment modality for substance use disorders. α 2A -adrenergic receptors (α 2A -ARs) in extended amygdala structures play key roles in dampening stress responses. Contrary to early thinking, α 2A -ARs are expressed at non-noradrenergic sites in the brain. These non-noradrenergic α 2A -ARs play important roles in stress responses, but their cellular mechanisms of action are unclear. In humans, the α 2A -AR agonist guanfacine reduces overall craving and uncouples craving from stress, yet minimally affects relapse, potentially due to competing actions in the brain. Here, we show that heteroceptor α 2A -ARs postsynaptically enhance dorsal bed nucleus of the stria terminalis (dBNST) neuronal activity in mice of both sexes. This effect is mediated by hyperpolarization-activated cyclic nucleotide-gated cation channels because inhibition of these channels is necessary and sufficient for excitatory actions. Finally, this excitatory action is mimicked by clozapine- N -oxide activation of the G i -coupled DREADD hM4Di in dBNST neurons and its activation elicits anxiety-like behavior in the elevated plus maze. Together, these data provide a framework for elucidating cell-specific actions of GPCR signaling and provide a potential mechanism whereby competing anxiogenic and anxiolytic actions of guanfacine may affect its clinical utility in the treatment of addiction. SIGNIFICANCE STATEMENT Stress affects the development of neuropsychiatric disorders including anxiety and addiction. Guanfacine is an α2A-adrenergic receptor (α2A-AR) agonist with actions in the bed nucleus of the stria terminalis (BNST) that produces antidepressant actions and uncouples stress from reward-related behaviors. Here, we show that guanfacine increases dorsal BNST neuronal activity through actions at postsynaptic α2A-ARs via a mechanism that involves hyperpolarization-activated cyclic nucleotide gated cation channels. This action is mimicked by activation of the designer receptor hM4Di expressed in the BNST, which also induces anxiety-like behaviors. Together, these data suggest that postsynaptic α2A-ARs in BNST have excitatory actions on BNST neurons and that these actions can be phenocopied by the so-called "inhibitory" DREADDs, suggesting that care must be taken regarding interpretation of data obtained with these tools., (Copyright © 2018 the authors 0270-6474/18/388923-21$15.00/0.)

In a prior report, we showed that extended-release guanfacine (GEXR) is safe and effective for children with autism spectrum disorder (ASD) accompanied by ADHD symptoms. Here, we examine the impact of GEXR on oppositional behavior, anxiety, repetitive behavior, and sleep disturbance. Sixty-two subjects with ASD (53 boys, 9 girls; ages 5-14 years) were randomly assigned to GEXR (n = 30) or placebo (n = 32) for 8 weeks. Outcomes include the Home Situation Questionnaire-Modified for ASD (HSQ-ASD), Anxiety scale of the Child and Adolescent Symptom Inventory (CASI), Children's Yale-Brown Obsessive-Compulsive Scale-Modified for ASD (CYBOCS-ASD), and Children's Sleep Habits Questionnaire (CSHQ). A repeated measures linear mixed model was used to determine the effects of treatment group and time on HSQ scores. For other measures, change from baseline was evaluated with Analysis of Covariance (ANCOVA).After 8 weeks of treatment, parent ratings of oppositional behavior on the HSQ declined by 44% (per item mean from 3.4 to 1.9) in the GEXR group compared to 12% (from 3.3 to 2.9) for placebo (p = 0.004). Repetitive behavior on the CYBOCS-ASD showed a significantly greater decline in GEXR-treated participants compared to placebo (24% vs. <1%, p = 0.01). No group differences were observed on CASI Anxiety or CSHQ (p = 0.64 and 0.75, respectively). GEXR was effective in reducing oppositional behavior and, more modestly, repetitive behavior. GEXR was not superior to placebo for anxiety, though baseline anxiety ratings were low. GEXR did not significantly improve sleep habits. Future studies could focus on repetitive behavior or anxiety, symptoms with limited treatment options.

Background: Guanfacine extended-release (GXR) is an orally administered, non-stimulant treatment for children and adolescents with attention-deficit/hyperactivity disorder (ADHD) and is primarily metabolized by the 3A4 isozyme of cytochrome P450 (CYP3A4). The results of clinical pharmacokinetic (PK) studies indicate that guanfacine is sensitive to drug-drug interactions (DDIs) perpetrated by strong inhibitors and inducers of CYP3A4., Objective: The aim was to provide guidance on the possible requirement for GXR dose adjustment in children and adolescents with ADHD by predicting DDIs following co-administration with moderate CYP3A4 inhibitors and inducers., Methods: A physiologically based PK model for GXR orally administered to healthy adults was developed based on physicochemical, in vitro and clinical PK data. The model was validated using clinical PK data for co-administration of GXR with ketoconazole (strong CYP3A4 inhibitor) or rifampicin (strong CYP3A4 inducer)., Results: Model predictions indicated that co-administration of GXR with the moderate CYP3A4 inhibitors erythromycin 500 mg three times a day or fluconazole 200 mg daily (q.d.) increased the guanfacine area under the plasma concentration-time curve (AUC) by 2.31-fold or 1.98-fold, respectively, compared with GXR monotherapy. The moderate CYP3A4 inducer efavirenz 400 mg or 600 mg q.d. was predicted to reduce guanfacine AUC to 58 or 33% of its value for GXR monotherapy, respectively., Conclusion: Without the requirement for additional clinical studies, the following GXR dose recommendations were developed and approved for US labeling for use in children and adolescents with ADHD: (1) decrease GXR to 50% of the usual target dose when it is co-administered with strong or moderate CYP3A4 inhibitors; (2) consider titrating GXR up to double the usual target dose over 1-2 weeks when it is co-administered with strong or moderate CYP3A4 inducers.

Objectives: To compare 1-year direct healthcare costs and utilization among children and adolescents initiating non-stimulant medications atomoxetine (ATX) or extended-release guanfacine (GXR)., Methods: In this retrospective, observational cohort study, children and adolescents aged 6-17 years with attention deficit/hyperactivity disorder (ADHD) who had ≥1 prescription claim for ATX or GXR between December 31, 2009 and January 1, 2011 were identified in the MarketScan Commercial or Multi-State Medicaid claims databases. The first claim was set as the index. Patients with no claims for other ADHD medications that overlapped with the days' supply for the index therapy during the post-period were classified as initiating monotherapy. All-cause and ADHD-related utilization and costs (2011 US$) and treatment patterns (adherence and persistence) were evaluated during the 12 months following index. Propensity score adjustment accounted for differences in patient characteristics, and bootstrapping was used for comparisons., Results: A total of 13,239 children and adolescents with ADHD met the study criteria (4,411 ATX initiators and 8,828 GXR initiators). There were 2,699 ATX monotherapy patients. In propensity-score-adjusted analyses, mean all-cause total costs were significantly less for monotherapy ATX initiators than for GXR initiators ($7,553 vs $10,639; difference = -$3,086, p < .0001), as were mean ADHD-related total costs ($3,213 vs $4,544; difference = -$1,330, p < .0001). Monotherapy ATX initiators had significantly fewer all-cause and ADHD-related total medical visits and ∼22 days shorter persistence to index therapy (p < .0001). Results were similar for secondary analyses comparing all ATX with all GXR initiators, regardless of monotherapy or combination regimen, and comparing only monotherapy initiators., Conclusions: Children and adolescents with ADHD who initiated ATX monotherapy incurred lower all-cause and ADHD-related total healthcare costs than patients who initiated GXR. This was due in part to less healthcare resource utilization and slightly shorter persistence for ATX patients. These findings may aid decision-making and inform future studies, but must be tempered due to inherent observational research limitations.

Objective: To evaluate children with ADHD and sleep problems with polysomnography (PSG) after guanfacine extended-release (GXR) administration., Method: Double-blind, randomized, placebo-controlled study was terminated early due to treatment-emergent concerns after enrolling 29 children aged 6 to 12 years. After >4 weeks dose adjustment and >1 week dose stabilization, 11 children received GXR and 16 controls underwent analyses with PSG., Results: Although GXR improved ADHD symptoms, the primary outcome variable, total sleep time, was shorter in contrast to placebo (-57.32, SD = 89.17 vs. +31.32, SD = 59.54 min, p = .005). Increased time awake after sleep onset per hour of sleep was the primary factor for the reduction. Although rapid eye movement (REM), non-REM, and N3/slow wave sleep times were reduced, these were proportional to the overall sleep reduction. Sedation was common with GXR (73% vs. 6%)., Conclusion: Morning-administered GXR resulted in decreased sleep and may contribute to sedation.

Background and Objective: Guanfacine extended-release (guanfacine XR) could be a useful treatment option for children and adolescent patients with attention-deficit/hyperactivity disorder (ADHD). As an initial step in the development in Japan, the pharmacokinetics, safety and tolerability were assessed in healthy Japanese and non-Hispanic Caucasian adults., Methods: A Phase 1, double-blind, randomized, placebo-controlled, single- and multiple-oral dose escalation study of guanfacine XR was conducted. Healthy Japanese and Caucasian subjects received guanfacine XR 1 mg orally in the morning on Day 1. Following safety assessments, subjects subsequently received guanfacine XR 1 mg (Days 4-8), 2 mg (Days 9-13), 3 mg (Days 14-18), and 4 mg (Days 19-23) once daily, followed by a taper-down period. Single- and multiple-dose pharmacokinetic parameters were estimated based on plasma concentration-time data and urine concentration data of guanfacine by non-compartmental analysis., Results: A total of 30 male subjects (15 Japanese and 15 Caucasian, active:placebo = 12:3) were enrolled. Of those receiving guanfacine XR, 11/12 (91.7%) subjects in each active drug group completed the study. Following multiple doses, the mean area under the plasma concentration-time curves of guanfacine were 9-22% greater for Caucasian subjects than Japanese subjects in the 1-3 mg dose range and 54% greater for the 4 mg. Guanfacine XR was generally well tolerated by both ethnic groups, with most adverse events being mild in both groups. There were no serious or severe adverse events during the study and no adverse events led to withdrawal from the study., Conclusions: Exposure to guanfacine in Japanese subjects tended to be lower than in Caucasian subjects. Guanfacine XR was generally well tolerated and safety profiles were similar for Japanese and Caucasian subjects.

This study compared the clinical efficacy and safety of attention-deficit/hyperactivity disorder (ADHD) pharmacotherapy in children and adolescents 6-17 years of age. A systematic literature review was conducted to identify randomized controlled trials (RCTs) of pharmacologic monotherapies among children and adolescents with ADHD. A Bayesian network meta-analysis was conducted to compare change in symptoms using the ADHD Rating Scale Version IV (ADHD-RS-IV), Clinical Global Impression-Improvement (CGI-I) response, all-cause discontinuation, and adverse event-related discontinuation. Thirty-six RCTs were included in the analysis. The mean (95% credible interval [CrI]) ADHD-RS-IV total score change from baseline (active minus placebo) was -14.98 (-17.14, -12.80) for lisdexamfetamine dimesylate (LDX), -9.33 (-11.63, -7.04) for methylphenidate (MPH) extended release, -8.68 (-10.63, -6.72) for guanfacine extended release (GXR), and -6.88 (-8.22, -5.49) for atomoxetine (ATX); data were unavailable for MPH immediate release. The relative risk (95% CrI) for CGI-I response (active versus placebo) was 2.56 (2.21, 2.91) for LDX, 2.13 (1.70, 2.54) for MPH extended release, 1.94 (1.59, 2.29) for GXR, 1.77 (1.31, 2.26) for ATX, and 1.62 (1.05, 2.17) for MPH immediate release. Among non-stimulant pharmacotherapies, GXR was more effective than ATX when comparing ADHD-RS-IV total score change (with a posterior probability of 93.91%) and CGI-I response (posterior probability 76.13%). This study found that LDX had greater efficacy than GXR, ATX, and MPH in the treatment of children and adolescents with ADHD. GXR had a high posterior probability of being more efficacious than ATX, although their CrIs overlapped.

Aim: To assess stimulant adherence among children/adolescents with attention-deficit/hyperactivity disorder (ADHD) augmenting stimulants with guanfacine extended-release (GXR)., Patients & Methods: Inclusion criteria: 6-17 years, ≥1 ADHD diagnosis, ≥1 long-acting and/or short-acting stimulant with GXR augmentation. Modified medication possession ratio (mMPR; days medication available/days in period, excluding medication holidays) was assessed; mMPR <0.80 nonadherent. Regression models assessed change in mMPR adjusting for demographic and clinical characteristics., Results: Among patients nonadherent to stimulants pre-augmentation (n = 165), unadjusted mean (SD) pre- and post-stimulant mMPRs were 0.68 (0.11) and 0.87 (0.16). Adjusted mean change in mMPR was 0.20 for long-acting versus 0.18 for short-acting stimulants (p = 0.34)., Conclusion: Among patients nonadherent to stimulants, GXR augmentation was associated with increased stimulant adherence.

Objective: This is a feasibility study evaluating the safety, tolerability, and potential anxiolytic efficacy of the α 2 agonist guanfacine extended-release (GXR) in children and adolescents with generalized anxiety disorder (GAD), separation anxiety disorder (SAD), or social phobia/social anxiety disorder., Methods: Youth aged 6-17 years with a primary diagnosis of GAD, SAD, and/or social anxiety disorder were treated with flexibly dosed GXR (1-6 mg daily, n = 62) or placebo (n = 21) for 12 weeks. The primary aim of this study was to determine the safety and tolerability of GXR in youth with anxiety disorders, which involved the analysis of treatment-emergent adverse events (TEAEs), the emergence of suicidal ideation and behaviors, vital signs, and electrocardiographic/laboratory parameters. Exploratory efficacy measures included dimensional anxiety scales (Pediatric Anxiety Rating Scale [PARS] and Screen for Child Anxiety Related Emotional Disorders [SCARED]), as well as the Clinical Global Impression-Improvement (CGI-I) scale. As this was an exploratory study, no inferential statistical analyses were performed., Results: GXR was safe and well tolerated. Treatment-related mean ± standard deviation changes in heart rate (GXR: 1.8 ± 12 beats per minute [bpm] decrease; placebo: 0.5 ± 11 bpm decrease), systolic blood pressure (GXR: 2.3 ± 11 mm Hg decrease; placebo: 1.7 ± 11 mm Hg decrease), or diastolic blood pressure (GXR: 1.3 ± 9 mm Hg decrease; placebo: 0.9 ± 7 mm Hg increase) were similar between treatment groups. TEAEs, including headache, somnolence/fatigue, abdominal pain, and dizziness, were consistent with the known safety profile of GXR. No differences were observed between treatment groups for PARS and SCARED scores, although at endpoint, a higher proportion of subjects receiving GXR versus placebo demonstrated CGI-I scores ≤2 (54.2% vs. 31.6%), as rated by the clinician investigator., Conclusions: GXR was well tolerated in pediatric subjects with GAD, SAD, and/or social anxiety disorder. ClinicalTrials.gov Identifier: NCT01470469.

Objective: To examine efficacy and safety of adjunctive guanfacine extended release (GXR) on morning and evening ADHD symptoms using the Conners' Global Index-Parent (CGI-P) and Before-School Functioning Questionnaire (BSFQ)., Method: Participants 6 to 17 years with ADHD ( N = 461) and suboptimal psychostimulant response were maintained on current psychostimulants and randomized to dose-optimized GXR (≤4 mg/d) in the morning (GXR AM) or evening (GXR PM), or placebo., Results: CGI-P scores improved with GXR (morning assessment, GXR AM, placebo-adjusted least squares [LS] mean = -1.7, GXR PM = -2.6; evening assessment, GXR AM = -2.4, GXR PM = -3.0; all ps < .01). Parent-rated BSFQ scores reflected improved morning functioning with GXR (GXR AM, placebo-adjusted LS mean = -5.1; GXR PM = -4.7; both ps < .01). Most adverse events were mild or moderate., Conclusion: Adjunctive GXR AM or GXR PM was associated with improvements in morning and evening ADHD symptoms in children and adolescents.

Objectives: This study examines cardiovascular (CV) effects of guanfacine immediate-release (GUAN-IR), dexmethylphenidate extended-release (DMPH), and their combination (COMB) during acute and long-term treatment of youth with attention-deficit/hyperactivity disorder., Methods: Two hundred seven participants aged 7-14 years enrolled in an 8-week double-blind randomized trial of GUAN-IR (1-3 milligrams (mg)/day), DMPH (5-20 mg/day), or COMB with fixed-flexible dosing and titrated to optimal behavioral response. Heart rate, systolic blood pressure (BP), diastolic BP, and electrocardiograms were assessed at baseline, end of blinded optimization, and over a 1-year open-label maintenance phase., Results: During acute titration, GUAN-IR decreased heart rate, systolic BP, and diastolic BP; DMPH increased heart rate, systolic BP, diastolic BP, and corrected QT (QTc) interval; COMB increased diastolic BP, but had no effects on heart rate, systolic BP, or QTc. During maintenance, GUAN-IR-associated decreases in heart rate and DMPH-associated increases in systolic BP returned to baseline values. Other variables across the three groups remained unchanged from the end of blinded titration. There were no discontinuations due to CV adverse events., Conclusion: GUAN-IR, DMPH, and COMB were well tolerated and safe. Expected changes in CV parameters during acute titration were seen in GUAN-IR and DMPH groups, with COMB values falling intermediately between the two other treatment groups. No serious CV events occurred in any participant. GUAN-IR- and DMPH-associated CV changes generally returned to baseline with sustained therapy. These data suggest that COMB treatment might attenuate long-term CV effects of GUAN-IR and stimulant monotherapy, possibly reducing risk of the small but statistically significant changes associated with either single treatment. Clinicaltrials.gov Identifier: NCT00429273.

Objective: To review currently available formulations and emphasize unmet needs in the pharmacologic management of attention-deficit/hyperactivity disorder (ADHD)., Data Sources: Publications and clinical trials were identified through PubMed and ClinicalTrials.gov, respectively. A Web-based search identified prescribing information for approved agents for treating ADHD, along with relevant guidelines and diagnostic criteria., Study Selection: The following search terms were used: (1) ADHD or attention-deficit/hyperactivity disorder or ADD or attention deficit hyperactivity disorder and/or (2) amphetamine or methylphenidate or atomoxetine or guanfacine or clonidine. Additional searches were performed using product brand names, and clinical trial was applied as a filter. Relevant studies were only included if published in English-language peer-reviewed journals and if involved agents were currently available (or pursuing approval) in the United States. Reviews of literature prior to 2005 and from 2005 to 2008 have been published previously; therefore, the present search focused on studies published from January 2009 through May 2016. In addition, reference lists of review articles and relevant studies were also examined to help identify additional studies., Data Extraction: A total of 578 publications were identified from the PubMed search, from which 426 publications were initially excluded based on review of the title and abstract. Reasons for exclusion included a focus on comorbid disorders, specific subpopulations, endpoints unrelated to improving ADHD symptomatology (eg, executive function, cognition, substance use), or quality of life measures. A more thorough assessment of the remaining citations, including publications and prescribing information, produced the final 219., Results: Pharmacotherapy with stimulant and nonstimulant options is the most common approach for treating ADHD in adults and children. Stimulants are mostly formulated as either tablets or capsules; however, the newer generation includes transdermal patches, oral suspensions (liquids), chewable tablets, and orally disintegrating tablets. Nonstimulants are available in oral capsule (atomoxetine) and tablet (guanfacine and clonidine) formulations., Conclusions: Despite the broad range of treatment options currently available, nonadherence remains a significant problem in ADHD. While evidence is currently lacking, the availability of new formulations may improve adherence., (© Copyright 2016 Physicians Postgraduate Press, Inc.)

Objective: Guanfacine, in the immediate release form, remains a commonly used medication for the treatment of clinically significant hyperactivity, impulsivity, or disruptive behaviors. This article reviews the available literature regarding guanfacine use in very young children (<6 years of age), and explores some of the factors that may uniquely impact the clinical pharmacology of guanfacine in very young children and that deserve consideration when it is used in this patient population., Methods: The authors performed electronic literature searches in PubMed through October 2015 using the terms attention-deficit/hyperactivity disorder, guanfacine, and alpha agonists. We also performed an informal review of the literature and used selected articles from relevant reference lists. The result was a broad, qualitative review of the literature, with a focus on specific factors regarding guanfacine use in very young children., Results: Despite the fact that guanfacine is commonly used in very young children, there is a paucity of published studies that looked specifically at its use in this population. In reviewing the pharmacology of guanfacine, there are specific factors that may play a unique role in its disposition in very young children., Conclusions: Guanfacine is an important medication option in very young children; however, there is a significant pharmacologic "information gap," and further research is needed to help establish appropriate, safe, and effective dosing of guanfacine in this population.

Objective: Psychostimulant medications are the gold standard of treatment for attention-deficit/hyperactivity disorder (ADHD); however, a significant minority (∼30%) of individuals with ADHD fail to respond favorably. Noradrenergic agents are increasingly used as ADHD monotherapies or adjuncts for suboptimal stimulant response, yet knowledge of their cortical effects is limited. This study is the first to examine comparative effects of guanfacine (an α adrenergic 2A agonist), psychostimulant, and their combination on resting state cortical activity in ADHD., Method: The sample comprised 179 participants aged 7 to 14 years old with ADHD (113 boys, 55 girls). Participants were randomized to 1 of 3 blinded conditions: guanfacine (GUAN), d-methylphenidate (DMPH), or the combination (COMB). Electroencephalography (EEG) was performed pre-, mid-, and post-medication titration, with concomitant assessment of behavioral and cognitive functioning., Results: Analyses of spectral power measures during resting EEG suggested that each medication condition displayed a distinct profile of effects on cortical activity. Significant time effects suggested that GUAN decreased global alpha band (8-12 hertz [Hz]) power, DMPH and COMB increased centro-parietal beta band (13-21 Hz) power, and COMB resulted in decreased theta band (4-7 Hz) power. Relative to other medication groups, COMB was associated with significantly lower theta band power and DMPH with higher beta band power compared with those in the GUAN group. Medication-related changes in theta power were correlated with improvements in behavioral and cognitive functioning., Conclusion: These data reveal distinct underlying medication-related effects on neural mechanisms. The COMB condition uniquely exhibited an EEG profile that was associated with improved behavioral and cognitive functioning. Clinical trial registration information-Single Versus Combination Medication Treatment for Children With Attention Deficit Hyperactivity Disorder; http://clinicaltrials.gov/; NCT00429273., Competing Interests: Loo, Cowen, Walshaw Welker, Levitt, Del’Homme, Mr. Cho, and Ms. Sturm report no biomedical financial interests or potential conflicts of interest., (Copyright © 2016 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.)

Objective: Psychostimulants are partially effective in reducing cognitive dysfunction associated with attention-deficit/hyperactivity disorder (ADHD). Cognitive effects of guanfacine, an alternative treatment, are poorly understood. Given its distinct action on α2A receptors, guanfacine may have different or complementary effects relative to stimulants. This study tested stimulant and guanfacine monotherapies relative to combined treatment on cognitive functions important in ADHD., Method: Children with ADHD (n = 182; aged 7-14 years) completed an 8-week, double blind, randomized, controlled trial with 3 arms: d-methylphenidate (DMPH), guanfacine (GUAN), or combination treatment with DMPH and GUAN (COMB). A nonclinical comparison group (n = 93) had baseline testing, and a subset was retested 8 weeks later (n = 38). Analyses examined treatment effects in 4 cognitive domains (working memory, response inhibition, reaction time, and reaction time variability) constructed from 20 variables., Results: The ADHD group showed impaired working memory relative to the nonclinical comparison group (effect size = -0.53 SD unit). The treatments differed in effects on working memory but not other cognitive domains. Combination treatment improved working memory more than GUAN but was not significantly better than DMPH alone. Treatment did not fully normalize the initial deficit in ADHD relative to the comparison group., Conclusion: Combined treatment with DMPH and GUAN yielded greater improvements in working memory than placebo or GUAN alone, but the combined treatment was not superior to DMPH alone and did not extend to other cognitive domains. Although GUAN may be a useful add-on treatment to psychostimulants, additional strategies appear to be necessary to achieve normalization of cognitive function in ADHD., Clinical Trial Registration Information: Single Versus Combination Medication Treatment for Children With Attention Deficit Hyperactivity Disorder; http://clinicaltrials.gov/; NCT00429273., (Copyright © 2016 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.)

Objective: Because models of attention-deficit/hyperactivity disorder (ADHD) therapeutics emphasize benefits of both enhanced dopaminergic and noradrenergic signaling, strategies to enhance D1 and α2A agonism may yield enhanced clinical and cognitive responses. This study tested the hypothesis that combined effects of a dopamine and noradrenergic agonist, d-methylphenidate extended-release (DMPH) with guanfacine (GUAN), an α2A receptor agonist, would be clinically superior to either monotherapy and would have equal tolerability., Method: An 8-week, double-blind, 3-arm, comparative trial randomized 7- to 14-year-olds with DSM-IV ADHD to GUAN (1-3 mg/day), DMPH (5-20 mg/day), or a combination (COMB) with fixed-flexible dosing. Outcome measures were the ADHD Rating Scale IV (ADHD-RS-IV) and the Clinical Global Impression-Improvement (CGI-I) scale. Data on adverse events and safety measures were obtained., Results: A total of 207 participants were randomized and received drug. Analyses showed significant treatment group main effects for ADHD-RS-IV ADHD total (p = .0001) and inattentive symptoms (p = .0001). COMB demonstrated small but consistently greater reductions in ADHD-RS-IV Inattentive subscale scores versus monotherapies (DMPH: p = .05; f(2) = .02; and GUAN: p = .02; f(2) = .02), and was associated with a greater positive response rate by CGI-I (p = .01). No serious cardiovascular events occurred. Sedation, somnolence, lethargy, and fatigue were greater in both guanfacine groups. All treatments were well tolerated., Conclusion: COMB showed consistent evidence of clinical benefits over monotherapies, possibly reflecting advantages of greater combined dopaminergic and α2A agonism. Adverse events were generally mild to moderate, and COMB treatment showed no differences in safety or tolerability., Clinical Trial Registration Information: Single Versus Combination Medication Treatment for Children With Attention Deficit Hyperactivity Disorder (Project1); http://clinicaltrials.gov/; NCT00429273., (Copyright © 2016 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.)

Objective: Treatment of obsessive-compulsive disorder (OCD) is complicated by comorbid psychiatric disorders. Successful treatment of 2 pediatric patients with severe OCD and comorbid attention deficit/hyperactivity disorder (ADHD) is described., Method: A report on 2 pediatric clinical cases (Ages 9 and 10) with comorbid OCD and ADHD was used to describe response to medication management through the serotonin transporter inhibitor, sertraline, and the noradrenergic α2A receptor agonist, guanfacine, along with cognitive behavioral therapy., Results: Cognitive behavioral therapy combined with titrated doses of the serotonin transporter inhibitor, sertraline, and the noradrenergic α2A receptor agonist, guanfacine resolved OCD symptoms and the underlying ADHD., Conclusion: The novel observations support a focused psychological and pharmacological approach to successful treatment of complex symptoms in patients with comorbid OCD and ADHD. Limitations to generalizability are discussed.

Background: Extended-release guanfacine hydrochloride (GXR), a selective α2A-adrenergic agonist, is a nonstimulant medication for attention-deficit/hyperactivity disorder (ADHD). This phase 3, double-blind, placebo-controlled, randomised-withdrawal study evaluated the long-term maintenance of GXR efficacy in children/adolescents with ADHD., Methods: Children/adolescents (6-17 years) with ADHD received open-label GXR (1-7 mg/day). After 13 weeks, responders were randomised to GXR or placebo in the 26-week, double-blind, randomised-withdrawal phase (RWP). The primary endpoint was the percentage of treatment failure (≥50% increase in ADHD Rating Scale version IV total score and ≥2-point increase in Clinical Global Impression-Severity compared with RWP baseline, at two consecutive visits). The key secondary endpoint was time to treatment failure (TTF)., Trial Registration: ClinicalTrials.gov identifier NCT01081145; EudraCT 2009-018161-12., Results: A total of 528 participants enrolled; 316 (59.8%) entered the RWP. Treatment failure occurred in 49.3% of the GXR and 64.9% of the placebo group (p = 0.006). TTF was significantly longer in GXR versus placebo (p = 0.003). GXR was well tolerated., Conclusions: Guanfacine hydrochloride demonstrated long-term maintenance of efficacy compared with placebo in children/adolescents with ADHD. Implications of the placebo substitution design and findings with different ADHD medications are discussed., (© 2016 The Authors. Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health.)

Aims: To assess the acute effects of intravenous guanfacine, an α2A-adrenergic agonist, on sympathetic outflow from the central nervous system and on sympathetic arterial pressure (AP) response., Main Methods: In anesthetized Wistar Kyoto rats, carotid sinus baroreceptor regions were isolated. Changes in electrical sympathetic nerve activity (SNA) and AP in response to a baroreceptor pressure input were examined before and after an intravenous administration of a high dose (100μg/kg, n=7) or a low dose (20μg/kg, n=5) of guanfacine., Key Findings: The higher dose of guanfacine significantly narrowed the range of the AP response (86.8±6.4 to 38.4±12.9mmHg, P<0.01) but increased the minimum AP (79.3±7.5 to 93.2±8.7mmHg, P<0.05). In the neural arc, guanfacine reduced both the response range (90.4±2.3 to 33.4±10.7%, P<0.01) and the minimum SNA (11.4±1.9 to 2.6±1.5%, P<0.01). In the peripheral arc, guanfacine increased the intercept (67.6±7.1 to 92.8±8.5mmHg, P<0.01) without a significant effect on the slope. The lower dose of guanfacine weakened the effects on both the neural and peripheral arcs., Significance: Guanfacine suppressed SNA without a significant reduction of AP, which may be attributable to the peripheral vasoconstrictive effect. Reducing the dose of acutely administered intravenous guanfacine does not aid in separating the central sympathoinhibitory effect from the peripheral vasoconstrictive effect on AP in anesthetized rats in vivo., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The purpose of this study was to examine the efficacy of an extended release guanfacine hydrochloride supplement relative to a placebo supplement in adults (19-62) with ADHD and a sub-optimal response to a stimulant-only treatment program. The study's primary outcome measures were the Attention Deficit Hyperactivity Disorder Rating Scale and the Clinical Global Impression - Severity. Twenty-six adults who met criteria for attention deficit hyperactivity disorder and sub-optimal functioning were randomly assigned to supplement their existing psychostimulant treatment regimen with either a titrated dose (1-6mg) of extended release guanfacine hydrochloride or a matching placebo for a 10-week trial. The data were analyzed with standard mixed model analysis of variance procedures, and participants in both the investigational agent group and the placebo group showed statistically significant improvement in their symptoms and functioning over the course of the trial. The treatments did not differ in terms of their efficacy, safety, or tolerability. Although these results do suggest that both treatments were associated with clinical improvement, the possible impacts of socially desirable responding and regression to the mean on these results are discussed., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Children/adolescents with attention-deficit/hyperactivity disorder (ADHD) may have a poor or inadequate response to psychostimulants or be unable to tolerate their side-effects; furthermore, stimulants may be inappropriate because of co-existing conditions. Only one non-stimulant ADHD pharmacotherapy, the noradrenaline transporter inhibitor atomoxetine, is currently approved for use in Europe. We review recent advances in understanding of the pathophysiology of ADHD with a focus on the roles of catecholamine receptors in context of the α2A-adrenergic receptor agonist guanfacine extended release (GXR), a new non-stimulant treatment option in Europe. Neuroimaging studies of children/adolescents with ADHD show impaired brain maturation, and structural and functional anomalies in brain regions and networks. Neurobiological studies in ADHD and medication response patterns support involvement of monoaminergic neurotransmitters (primarily dopamine and noradrenaline). Guanfacine is a selective α2A-adrenergic receptor agonist that has been shown to improve prefrontal cortical cognitive function, including working memory. The hypothesized mode of action of guanfacine centres on direct stimulation of post-synaptic α2A-adrenergic receptors to enhance noradrenaline neurotransmission. Preclinical data suggest that guanfacine also influences dendritic spine growth and maturation. Clinical trials have demonstrated the efficacy of GXR in ADHD, and it is approved as monotherapy or adjunctive therapy to stimulants in Canada and the USA (for children and adolescents). GXR was approved recently in Europe for the treatment of ADHD in children and adolescents for whom stimulants are not suitable, not tolerated or have been shown to be ineffective. GXR may provide particular benefit for children/adolescents who have specific co-morbidities such as chronic tic disorders or oppositional defiant disorder (or oppositional symptoms) that have failed to respond to first-line treatment options.

Objective: Hyperactivity, impulsiveness, and distractibility are common problems in children with autism spectrum disorder (ASD). Extended-release guanfacine is approved for children with attention deficit hyperactivity disorder but not well studied in ASD., Method: In a multisite, randomized clinical trial, extended-release guanfacine was compared with placebo in children with ASD accompanied by hyperactivity, impulsiveness, and distractibility., Results: Sixty-two subjects (boys, N=53; girls, N=9; mean age=8.5 years [SD=2.25]) were randomly assigned to guanfacine (N=30) or placebo (N=32) for 8 weeks. The guanfacine group showed a 43.6% decline in scores on the Aberrant Behavior Checklist-hyperactivity subscale (least squares mean from 34.2 to 19.3) compared with a 13.2% decrease in the placebo group (least squares mean from 34.2 to 29.7; effect size=1.67). The rate of positive response (much improved or very much improved on the Clinical Global Impression-Improvement scale) was 50% (15 of 30) for guanfacine compared with 9.4% (3 of 32) for placebo. A brief cognitive battery tapping working memory and motor planning showed no group differences before or after 8 weeks of treatment. The modal dose of guanfacine at week 8 was 3 mg/day (range: 1-4 mg/day), and the modal dose was 3 mg/day (range: 2-4 mg/day) for placebo. Four guanfacine-treated subjects (13.3%) and four placebo subjects (12.5%) exited the study before week 8. The most common adverse events included drowsiness, fatigue, and decreased appetite. There were no significant changes on ECG in either group. For subjects in the guanfacine group, blood pressure declined in the first 4 weeks, with return nearly to baseline by endpoint (week 8). Pulse rate showed a similar pattern but remained lower than baseline at endpoint., Conclusions: Extended-release guanfacine appears to be safe and effective for reducing hyperactivity, impulsiveness, and distractibility in children with ASD.

Background: In clinical trials of medications to treat attention-deficit/hyperactivity disorder (ADHD) in children, effects on functional impairment have been less well-studied than changes in ADHD symptoms., Objective: Data regarding functional impairment were analyzed from a multicenter, double-blind, placebo-controlled study of guanfacine extended release (GXR) in children with ADHD, using the Weiss Functional Impairment Rating Scale-Parent Report (WFIRS-P). The correspondence of changes in WFIRS-P scores with symptomatic and global response to GXR treatment was also examined, with treatment response defined by scores on both the ADHD Rating Scale IV (ADHD-RS-IV) and the Clinical Global Impressions-Improvement Scale (CGI-I)., Methods: In this 8-week, double-blind, placebo-controlled, dose optimization study at 47 sites across the USA and Canada, children aged 6-12 years with a diagnosis of ADHD [Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria, and an ADHD-RS-IV score ≥28 and CGI-Severity of Illness Scale score ≥4 at baseline], were randomized 1:1:1 into three groups: GXR AM [GXR (1-4 mg/day) in the morning, placebo in the evening], GXR PM [placebo in the morning, GXR (1-4 mg/day) in the evening], or twice-daily placebo. Parents rated their children on the WFIRS-P at screening, baseline, the end of dose optimization, and at the final on-treatment assessment., Results: The efficacy population was composed of 333 subjects (GXR AM: n = 107; GXR PM: n = 114; placebo: n = 112). At the final on-treatment assessment, there were significant improvements from baseline in the placebo-adjusted difference in least-squares (LS) mean (95 % confidence interval) WFIRS-P Total scores for both GXR treatment groups combined [GXR all-active: -0.16 (-0.25, -0.07), effect size (ES) = 0.448, P <0.001] and separately [GXR AM: -0.15 (-0.26, -0.05), ES = 0.417, P = 0.004; GXR PM: -0.18 (-0.28, -0.07), ES = 0.478, P = 0.001]. Significant improvements in WFIRS-P domain scores for Family, Learning and School (including Academic Performance and Behavior in School), Social, and Risky Behavior were found for both GXR cohorts compared with placebo. However, the Life Skills and Self-Concept domain scores of the WFIRS-P did not improve with GXR treatment. Post hoc stratification by responder status revealed that significant (P <0.001) improvements in WFIRS-P Total and all domain scores were associated with symptomatic treatment response in the GXR all-active group., Conclusions: GXR treatment in children with ADHD was associated with reductions in WFIRS-P functional impairment scores compared with placebo, regardless of time of GXR administration. Changes in WFIRS-P scores were congruent with clinical response, as determined by both ADHD symptom reduction and CGI-I scores. CLINICALTRIALS., Gov Identifier: NCT00997984.

Objective: Despite the continuity of attention-deficit/hyperactivity disorder (ADHD) into adolescence, little is known regarding use of nonstimulants to treat ADHD in adolescents. This phase 3 trial evaluated the safety and efficacy of guanfacine extended release (GXR) in adolescents with ADHD., Method: This 13-week, multicenter, randomized, double-blind, placebo-controlled trial evaluated once-daily GXR (1-7 mg per day) in adolescents with ADHD aged 13 to 17 years. The primary endpoint was the change from baseline in the ADHD Rating Scale-IV (ADHD-RS-IV) total score; key secondary endpoints included scores from the Clinical Global Impressions-Severity of Illness (CGI-S), and Learning and School domain and Family domain scores from the Weiss Functional Impairment Rating Scale-Parent Report (WFIRS-P) at week 13., Results: A total of 314 participants were randomized (GXR, n = 157; placebo, n = 157). The majority of participants received optimal doses of 3, 4, 5, or 6 mg (30 [22.9%], 26 [19.8%], 27 [20.6%], or 24 [18.3%] participants, respectively), with 46.5% of participants receiving an optimal dose above the currently approved maximum dose limit of 4 mg. Participants receiving GXR showed improvement in ADHD-RS-IV total score compared with placebo (least-squares mean score change, -24.55 [GXR] versus -18.53 [placebo]; effect size, 0.52; p <.001). More participants on GXR also showed significant improvement in CGI-S scores compared with placebo (50.6% versus 36.1%; p = .010). There was no statistically significant difference between treatments at week 13 in the 2 WFIRS-P domains. Most treatment-emergent adverse events were mild to moderate, with sedation-related events reported most commonly., Conclusion: GXR was associated with statistically significant improvements in ADHD symptoms in adolescents. GXR was well tolerated, with no new safety signals reported., Clinical Trial Registration Information: Dose-Optimization in Adolescents Aged 13-17 Diagnosed With Attention-Deficit/Hyperactivity Disorder (ADHD) Using Extended-Release Guanfacine HCl; http://ClinicalTrials.gov/; NCT01081132., (Copyright © 2015. Published by Elsevier Inc.)

The search for drugs with anorectic activity, acting within the adrenergic system has attracted the interest of researchers. Partial α2-adrenoceptor agonists might offer the potential for effective and safe treatment of obesity. We compared the effectiveness and safety of α2-adrenoceptor ligands in reducing body mass. We also analyzed if antagonist and partial agonists of α2-adrenoceptor--yohimbine and guanfacine--act similarly, and determined which course of action is connected with anorectic activity. We tested intrinsic activity and effect on the lipolysis of these compounds in cell cultures, evaluated their effect on meal size, body weight in Wistar rats with high-fat diet-induced obesity, and determined their effect on blood pressure, heart rate, lipid profile, spontaneous locomotor activity, core temperature and glucose, as well as glycerol and cortisol levels. Both guanfacine and yohimbine showed anorectic activity. Guanfacine was much more effective than yohimbine. Both significantly reduced the amount of intraperitoneal adipose tissue and had a beneficial effect on lipid profiles. Decreased response of α2A-adrenoceptors and partial stimulation of α2B-receptors seem to be responsible for the anorectic action of guanfacine. The stimulation of α1-adrenoceptors by guanfacine is responsible for cardiovascular side effects but may also be linked with improved anorexic effect. α1-adrenoceptor blockade is connected with the side effects of yohimbine, but it is also associated with the improvement of lipid profiles. Guanfacine has been approved by the Food and Drug Administration (FDA) to treat hypertension and conduct disorder, but as it reduces body weight, it is worth examining its effectiveness and safety in models of obesity.

Background: While step therapy (ST) policies are generally effective at reducing cost through the managed utilization of targeted medications, the clinical implications of ST policies are not clear and may vary across therapeutic areas. Guanfacine extended-release (GXR) is approved by the FDA for the treatment of attention-deficit/hyperactivity disorder (ADHD) as both monotherapy and adjunctive to stimulant treatment. At the introduction of GXR to the market, Humana implemented an ST policy on GXR requiring the documentation of previous treatment, intolerance, or contraindication to generic clonidine or guanfacine., Objective: To examine the impact of a GXR ST coverage determination (i.e., approved vs. denied) on medication utilization and health care costs among members of a commercial health plan with an ST policy for GXR. , Methods: This study was a retrospective cohort study of administrative claims data. Humana commercial members prescribed GXR who had an ST coverage determination review were identified. All members included in this analysis were required to be aged 6-17 years, have a diagnosis of ADHD or be receiving stimulant medication, have an ST coverage determination (index event) between September 1, 2009, and May 30, 2012, and have 6 months of pre- and post-index continuous enrollment. Members were assigned to either the approved or denied group based on the outcome of the ST coverage determination. Medical and pharmacy claims data were used to measure baseline demographic and clinical characteristics and to measure medication utilization and health care costs. Outcomes assessed during follow-up included ADHD medication use, proportion of days covered (PDC) with any ADHD medication treatment, time to first observed post-index ADHD treatment, and all-cause and mental health (MH)-related health care costs. Administrative costs associated with the coverage determination process were also estimated. Bivariate and multivariable adjusted analyses were conducted to compare medication utilization and health care costs between the approved and denied groups., Results: A total of 642 members were included in the analysis (denied group n = 395 [61.5%], approved group n = 247 [38.5%]). The approved and denied groups were similar in terms of baseline demographics, provider characteristics, and baseline MH diagnoses, with the exception of anxiety disorders being more prevalent in the approved group compared with the denied group (18.2% vs. 10.6%, P = 0.006). A denied GXR coverage determination was associated with a greater percentage of members receiving no ADHD treatment post-index (13.9% vs. 3.2%, P  less than  0.001), greater mean [SD] number of days between index and first observed post-index ADHD medication claim (44.5 [59.6] vs. 17.6 [33.4], P  less than  0.001), and lower mean [SD] PDC with any ADHD medication post-index (0.59 [0.33] vs. 0.75 [0.26], P  less than  0.001). These findings remained statistically significant in multivariable regression models. Unadjusted pre-index median total health care costs and MH-related costs were greater among the approved group compared with the denied group (total health care: $1,582 vs. $1,465, P = 0.033; MH-related: $993 vs. $981, P = 0.020). Likewise, post-index median total health care and MH-related costs were greater among the approved group compared with the denied group (total: $2,056 vs. $1,420, P  less than  0.001; MH-related: $1,543 vs. $946, P  less than  0.001). After adjustment for potentially confounding covariates including pre-index costs, there were no statistically significant differences between the approved and denied groups in all-cause total health care (P = 0.393) or MH-related health care costs (P = 0.054). , Conclusions: The current study found that GXR coverage denial was associated with lower rate of ADHD medication utilization, greater delay in receiving ADHD medication, and lower PDC with ADHD medication. There were no differences observed between the approved and denied group in terms of all-cause total health care or MH-related total health care costs after controlling for potentially confounding variables. Prior to implementation in the ADHD therapeutic area and others, payers should consider the potentially unintended consequences of ST policies, including delay in treatment and undertreatment.

Introduction: The population pharmacokinetics of guanfacine extended release were characterized in pediatric patients aged 6-17 years using NONMEM and evaluated by predictive check and bootstrap., Methods: Data were described using a one-compartment model. A covariate modeling approach that emphasized parameter estimation rather than stepwise hypothesis testing was implemented. A nonparametric bootstrap procedure and a predictive check method were used to evaluate the final model and parameter estimates., Results: Typical population pharmacokinetic parameters (95 % confidence interval), given the reference covariates (Caucasian, male, age 12 years, weight 50 kg), were 33.1 (30.2-36.4) L/h for apparent clearance (CL/F), 804 (703-900) L for apparent volume of distribution, 0.552 (0.437-0.670) h(-1) for the absorption rate constant, and 0.651 (0.608-0.697) h for absorption lag time., Discussion: The pharmacokinetics of guanfacine are similar in pediatric patients compared with adults when appropriately scaled by patient weight. The main predictor of guanfacine exposure, as determined by a change in CL/F, was weight. Effects of the other covariates (age, sex, and race) on CL/F were estimated with reasonable precision; however, the additional effects of age, sex, and race can be considered to have little to no clinical relevance.

Twenty-five youth with attention-deficit/hyperactivity disorder (ADHD) were scanned with functional magnetic resonance imaging (fMRI) while performing a Go/No-go task before and after 6-8 weeks of randomized once-daily treatment with either the α₂A-adrenergic receptor agonist guanfacine or placebo. Clinical improvement was greater for guanfacine than placebo and was differentially associated with reduced activation for guanfacine compared with placebo in the right midcingulate cortex/supplementary motor area and the left posterior cingulate cortex., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)