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Aims: Phosphodiesterase 2 (PDE2) regulates intracellular cyclic adenosine monophosphate and guanosine monophosphate (cAMP/cGMP) levels, which contribute to processes crucial for learning and memory. BI 474121, a potent and selective PDE2 inhibitor, is in development for treating cognitive impairment associated with schizophrenia., Methods: The effects of BI 474121 on cGMP concentrations were first assessed in rat cerebrospinal fluid (CSF) to demonstrate central nervous system (CNS) and functional target engagement. Next, a Phase I study in healthy participants assessed the pharmacokinetics of BI 474121 in CSF vs. plasma, the pharmacodynamics of BI 474121 by measuring cGMP concentrations in the CSF, and the safety of BI 474121., Results: In rats, BI 474121 was associated with a dose-dependent increase (71% at the highest dose tested [3.0 mg kg -1 ]) in cGMP levels in the CSF relative to vehicle (P < 0.001). In healthy participants, the maximum-measured concentration CSF-to-plasma ratio for BI 474121 exposure was similar following single oral doses of BI 474121 2.5, 10, 20 and 40 mg (dose-adjusted geometric mean: 8.96% overall). BI 474121 2.5-40 mg administration in healthy participants also increased cGMP levels in CSF (maximum exposure-related change from baseline ratio, BI 474121: 1.44-2.20 vs. placebo: 1.26). The most common treatment-emergent adverse event (AE) was mild-to-moderate post-lumbar puncture syndrome, which resolved with standard treatment. No AEs of special interest were observed., Conclusions: BI 474121 crosses the blood-brain barrier to inhibit PDE2, supporting cGMP as a translational marker to monitor CNS target engagement. These findings promote further clinical development of BI 474121., Clinicaltrials: gov number (NCT04672954)., (© 2024 The Author(s). British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Background: Cognitive impairment associated with schizophrenia predicts poor functional outcomes, but currently no efficacious pharmacotherapies are available., Aims: Four phase I trials examined the safety, tolerability and pharmacokinetics of the phosphodiesterase 2 inhibitor BI 474121, along with potential drug-drug interactions., Methods: Trial 1 evaluated single rising doses (SRDs) of BI 474121 versus placebo in healthy males. The influence of drug formulation and food on drug bioavailability was also examined. Trial 2 evaluated SRD of BI 474121 versus placebo in healthy Japanese males. Trial 3 evaluated multiple rising doses of BI 474121 in healthy young (with/without midazolam) and elderly (without midazolam) participants versus placebo. Trial 4 investigated interactions between itraconazole and single-dose BI 474121 in healthy males., Results/outcomes: No deaths, serious adverse events (AEs), severe AEs or protocol-specified AEs of special interest were observed. BI 474121 absorbed rapidly during fasting, achieved maximum concentration of analyte in plasma and dose proportionality via tablet formulation, and decreased in a multiphasic manner. BI 474121 steady state occurred within 11 days of multiple oral administration. Multiple doses increased BI 474121 plasma concentrations, but did not alter the time course of plasma concentrations. Urinary excretion of unchanged BI 474121 was negligible. No clinically relevant inhibition or induction of CYP3A4 by BI 474121 was observed. Itraconazole co-administration produced higher exposures of BI 474121 versus BI 474121 alone., Conclusions/interpretation: BI 474121 demonstrated favourable safety and pharmacokinetic profiles in healthy Caucasian and Japanese individuals, supporting further clinical development., Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship and/or publication of this article: JS, AS, R-GG and NY are employees of Boehringer Ingelheim but received no direct compensation related to the development of this manuscript.

Background: PDE10A inhibition represents a potential mechanism for treating schizophrenia. PDE10A inhibitors increase cyclic nucleotides in striatal neurons, thereby mimicking the effects of dopamine receptor D2 antagonists and D1 agonists. We evaluated the PDE10A inhibitor MK-8189 for treating schizophrenia., Methods: Randomized, double-blind, placebo and active-controlled, phase 2a, multicenter, inpatient trial in adults experiencing an acute episode of schizophrenia. Participants were randomized 2:2:1 to once-daily MK-8189 12 mg, placebo, or risperidone 6 mg (active control) for 4-weeks. The primary outcome was change-from-baseline in total score on the Positive and Negative Syndrome Scale (PANSS) at 4 weeks., Results: The number of treated participants was 90 for MK-8189, 89 for placebo, and 45 for risperidone. MK-8189 demonstrated a trend towards improvement versus placebo for change-from-baseline in PANSS total score after 4 weeks (difference = -4.7 [95 % CI: -9.8,0.5], P = 0.074). The active control risperidone was superior to placebo on PANNS total score (difference = -7.3 [95 % CI: -14.0,-0.6], P = 0.033), demonstrating assay sensitivity, while MK-8189 and risperidone did not significantly differ (difference = 2.6 [95 % CI: -4.0,9.2], P = 0.440). MK-8189 had a nominally significant effect on PANSS positive subscale score compared to placebo (difference = -2.2 [95 % CI: -3.8,-0.5], P = 0.011). Discontinuation of MK-8189 treatment due to an adverse event was low (<10 %). Extrapyramidal symptoms occurred with MK-8189 but were mostly mild and transient. Compared with placebo, MK-8189 reduced body weight while risperidone increased weight., Conclusions: These findings suggest that PDE10A inhibition may produce antipsychotic effects and associated weight loss and that further trials with PDE10A inhibitors are warranted., Trial Registration: Clinicaltrials.gov identifier: NCT03055338., Competing Interests: Declaration of competing interest Mukai, Lupinacci, Snow-adami, Voss, Smith, and Egan are employees of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co. Inc., Rahway, NJ, USA (MSD) and own stock/stock options in Merck & Co., Inc., Rahway, NJ, USA. Marder has acted as a consultant for MSD., (Copyright © 2024. Published by Elsevier B.V.)

Asthma is a heterogeneous, chronic respiratory disease characterized by airway inflammation and remodeling. Phosphodiesterase (PDE) inhibitors represent one of the intensively studied groups of potential anti-asthmatic agents due to their affecting both airway inflammation and remodeling. However, the effect of inhaled pan-PDE inhibitors on allergen induced asthma has not been reported to date. In this study we investigated the impact of two, representative strong pan-PDE inhibitors from the group of 7,8-disubstituted derivatives of 1,3-dimethyl-3,7-dihydro-1H-purine-2,6-dione: compound 38 and 145, on airway inflammation and remodeling in murine model of ovalbumin (OVA)-challenged allergic asthma. Female Balb/c mice were sensitized and challenged with OVA, 38 and 145 were administrated by inhalation, before each OVA challenge. The inhaled pan-PDE inhibitors markedly reduced the OVA-induced airway inflammatory cell infiltration, eosinophil recruitment, Th2 cytokine level in bronchoalveolar lavage fluid, as well as both, total and OVA-specific IgE levels in plasma. In addition, inhaled 38 and 145 decreased many typical features of airway remodeling, including goblet cell metaplasia, mucus hypersecretion, collagen overproduction and deposition, as well as Tgfb1, VEGF, and α-SMA expression in airways of allergen challenged mice. We also demonstrated that both 38 and 145 alleviate airway inflammation and remodelling by inhibition of the TGF-β/Smad signaling pathway activated in OVA-challenged mice. Taken together, these results suggest that the investigated pan-PDE inhibitors administered by inhalation are dual acting agents targeting both airway inflammation and remodeling in OVA-challenged allergic asthma and may represent promising, anti-asthmatic drug candidates., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: E2027 is a novel, highly selective and potent inhibitor of phosphodiesterase 9 in development for dementia with Lewy bodies. Cardiac safety assessments for emerging agents are essential to avoid drug-induced QT interval prolongation, which may predispose individuals to potentially fatal ventricular arrhythmias. To evaluate the cardiac safety of E2027 and to inform dose selection for the phase 2 study of E2027 in dementia with Lewy bodies, we evaluated concentration-response modeling of pooled electrocardiogram data., Patients and Methods: A post hoc concentration-QTc analysis evaluated potential QT effects using data from 2 randomized, double-blind studies in healthy subjects: a single ascending dose (SAD) study and a multiple ascending dose (MAD) study. Daily E2027 doses ranged from 5 to 1200 mg., Results: A linear mixed-effects model was used to establish the relationship between plasma concentrations of E2027 and change from the baseline of QTcF (ΔQTcF). A significant but shallow relationship was observed in the estimated slope of the concentration-ΔQTcF: 0.002 ms/ng/mL (90% confidence interval: 0.0007-0.0031) with a small, nonsignificant treatment effect-specific intercept of -0.6 ms. Based on this pooled concentration-QTc analysis, an effect on the QTcF interval >10 ms can be excluded up to E2027 plasma concentrations of ∼3579 ng/mL, corresponding to a dose at least 4-fold larger than the 50 mg phase 2 dose., Conclusion: This pooled post hoc analysis evaluating cardiac safety of E2027 demonstrated that clinically concerning QTcF prolongation and related cardiac complications are highly unlikely with proposed E2027 doses planned for phase 2., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Aims: To determine whether phosphodiesterase inhibitors (PDEi) or α-antagonists (AA) were associated with differences in region of interest (ROI) characteristics or prostate cancer detection on fusion biopsy (FB)., Materials and Methods: Records from 847 consecutive patients undergoing FB at three separate institutions over a period of 2 years were retrospectively reviewed. Associations between medication use, Prostate Imaging Reporting & Data System (PIRADS) scores, and ROI locations were assessed with ordinal logistic regression. Associations with lesion size and International Society of Urologic Pathology (ISUP) grade group (GG) on biopsy were tested using multivariate regression., Results: Medication use included PDEi in 14.2% and AA in 23.0%. PDEi use was associated with 19.3% smaller lesion diameter (-2.8 mm; CI from -4.8 to -0.7; p < 0.01) and lower PIRADS scores on MRI (OR 0.60; CI 0.40 - 1.00; p = 0.05). AA use was associated with higher PIRADS scores (OR 1.43; CI 0.97 - 2.11; p = 0.06), fewer positive fusion-directed biopsy cores (-28.6%, CI from -57.9 to 0.01%, p = 0.05), and downgrading on final pathology (-19%; CI from -40 to 2%; p = 0.06)., Conclusion: For PIRADS scores ≥ 3, PDEi use is associated with smaller ROI and lower PIRADS scores, while AA use is associated with higher PIRADS scores. Neither medication was associated with differences in biopsy GG. Prospective studies are needed to investigate the discordance between multi-parametric magnetic resonance imaging (mpMRI) results and oncologic outcomes associated with PDEi and AA use.

Background: Sildenafil citrate is a commonly used medication for the management of erectile dysfunction. Previous studies have described some neuropsychiatric side effects of this medication. So far, however, there has been little discussion about sildenafil-induced psychosis., Case Presentation: We here present the case of a 32-year-old Iranian male, without a known psychiatric history, who developed psychotic symptoms following initiation of sildenafil. We also postulate a mechanism by which this may occur., Conclusions: This report highlights the importance of watchful observation for the occurrence of this rare but serious side effect. Further studies are needed to clarify the precise mechanism that causes sildenafil-induced psychosis., (© 2022. The Author(s).)

Hyperserotonemia, during the early developmental phase, generates behavioral and biochemical phenotypes associated with autism spectrum disorder (ASD) in rats. Phosphodiesterase‑1 (PDE1) inhibitors are known to provide benefits in various brain conditions. We investigated the role of a selective PDE1 inhibitor, vinpocetine on ASD‑related behavioral phenotypes (social behavioral deficits, repetitive behavior, anxiety, and hyperlocomotion) in a developmental hyperserotonemia (DHS) rat model. Also, effects on biochemical markers related with neuronal function brain derived neurotrophic factor (BDNF) and phosphorylated cAMP response element binding protein (pCREB), inflammation interleukins (IL‑6 and IL‑10) and tumor necrosis factor-alpha (TNF‑α), and oxidative stress (TBARS and GSH) were studied in important brain areas (frontal cortex, cerebellum, hippocampus, and striatum). Administration of 5‑methoxytryptamine (5‑MT) to rats prenatally (gestational day 12) and in early developmental stages postnatal day (PND 0 - PND 20), resulted in impaired behavior and brain biochemistry. Administration of vinpocetine daily (10 and 20 mg/kg) to 5‑MT rats from PND 21 to PND 48 resulted in an improvement of behavioral deficits. Also, vinpocetine administration significantly increased the levels of BDNF, ratio of pCREB/ CREB, IL‑10, and GSH, and significantly decreased TNF‑α, IL‑6, and TBARS levels in different brain areas. Finally, our correlation analysis indicated that behavioral outcomes were significantly associated with the biochemical outcome. Vinpocetine, a selective PDE1 inhibitor, rectified important behavioral phenotypes related with ASD, possibly by improving markers of neuronal function, brain inflammation, and brain oxidative stress. Thus, PDE1 could be a potential target for pharmacological interventions and furthering our understanding of ASD pathogenesis.

Objective: Currently, no NASH-specific therapies are approved by the US Food and Drug Administration. This study aimed to compare the clinical effect of vitamin E (Vit. E), Ursodeoxycholic Acid (UDCA) and pentoxifylline (PTX) on Egyptian patients with NASH with exploration of their possible roles on inflammatory cytokines and chemokines mainly Interleukin 6 (IL6) and Monocyte Chemoattractant Protein-1 (CCL2/MCP-1)., Patients and Methods: We conducted a 3-month, randomized, single-blind study in 102 Egyptian NASH patients who were divided into three groups; group 1 received Vit. E 400 mg twice a day, group 2 received UDCA 250 mg twice a day and group 3 received PTX 400 mg twice daily. Liver aminotransferases (AST, ALT), IL6, CCL2/MCP-1, albumin, bilirubin, and lipid panel were measured both before and after intervention intake., Results: A significant decrease was found in liver aminotransferases, serum cytokine and chemokine in participants after Vit. E, UDCA or PTX intake. Compared to the UDCA and PTX groups, liver aminotransferases, serum cytokine and chemokine showed a more statistically significant reduction after Vit. E administration (50%, 43%, 57% and 55% for ALT, AST, IL6 and CCL2/MCP-1, respectively). In contrast, other biochemical tests showed non-significant change after any drug intake. None of the tested drugs showed significant safety issues in this population., Conclusions: Treatment with Vit. E, UDCA and PTX was both safe and effective in improving hepatic aminotransferases and inflammatory markers in Egyptian NASH patients. The superior effect of Vit. E compared to UDCA and PTX may suggest that oxidative stress plays a key role in disease progression of NASH patients. Moreover, IL6 and CCL2/MCP-1 may be used with or without ALT for treatment evaluation of NASH people.

Background : The pharmacokinetics (PK), safety, and tolerability profiles of ZSP1601, a first-in-class pan-phosphodiesterase (PDE) inhibitor, were evaluated in healthy Chinese volunteers. Research design and methods : This Phase 1a study consisted of a double-blinded, randomized, placebo-controlled single ascending dose (SAD) (25 to 350 mg), multiple ascending doses (MAD) (50 or 100 mg QD), and a two-period crossover food effect study (100 mg). Results : ZSP1601 was quickly absorbed, with maximum plasma concentrations (C max ) reached at 1.25 to 2.50 h (median T max ). The exposures exhibited dose-proportional increases, while the mean half-life (t1/2) ranged from 6.34-8.64 h. Steady-state was reached within seven days in the MAD study. The mean steady trough concentrations were 423 and 588 ng/mL, respectively. ZSP1601 accumulation was low, with ratios ≤ 1.5. The bioavailability of ZSP1601 was equivalent under fasted and fed states. All adverse events (AEs) were assessed as mild or moderate, with headaches as the most common. The highest single doses (275 and 350 mg) yielded more AEs, yet the rates were similar with the placebo cohorts in the MAD study. Conclusions : The safety and PK profiles of ZSP1601 support further efficacy evaluation in nonalcoholic steatohepatitis patients. Trial registration : The trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT03392779).

Introduction: Cyclic nucleotides, cAMP, and cGMP, are important second messengers of intracellular signaling and play crucial roles in cardiovascular biology and diseases. Cyclic nucleotide phosphodiesterases (PDEs) control the duration, magnitude, and compartmentalization of cyclic nucleotide signaling by catalyzing the hydrolysis of cyclic nucleotides. Individual PDEs modulate distinct signaling pathways and biological functions in the cell, making it a potential therapeutic target for the treatment of different cardiovascular disorders. The clinical success of several PDE inhibitors has ignited continued interest in PDE inhibitors and in PDE-target therapeutic strategies., Areas Covered: This review concentrates on recent research advances of different PDE isoforms with regard to their expression patterns and biological functions in the heart. The limitations of current research and future directions are then discussed. The current and future development of PDE inhibitors is also covered., Expert Opinion: Despite the therapeutic success of several marketed PDE inhibitors, the use of PDE inhibitors can be limited by their side effects, lack of efficacy, and lack of isoform selectivity. Advances in our understanding of the mechanisms by which cellular functions are changed through PDEs may enable the development of new approaches to achieve effective and specific PDE inhibition for various cardiac therapies.

Background: TAK-063 is an inhibitor of phosphodiesterase 10A (PDE10A), an enzyme highly expressed in medium spiny neurons of the striatum. PDE10A hydrolyzes both cyclic adenosine monophosphate and cyclic guanosine monophosphate and modulates dopamine signaling downstream of receptor activation in both direct and indirect pathways of the striatum. TAK-063 exhibited antipsychotic-like effects in animal models; however, the translatability of these models to the clinical manifestations of schizophrenia and the meaningfulness for new targets such as PDE10A has not been established., Methods: The TAK-063 phase 1 program included a comprehensive translational development strategy with the main objective of determining whether the antipsychotic-like pharmacodynamic effects seen in nonclinical models would translate to human subjects. To evaluate this objective, we conducted a single-rising dose study (84 healthy subjects), a positron emission tomography (PET) study (12 healthy subjects), a functional magnetic resonance imaging blood oxygen level-dependent (BOLD) study (27 healthy subjects), and a multiple-rising dose study that included people with schizophrenia (30 healthy Japanese subjects and 47 subjects with stable schizophrenia). In addition, assessments of cognition and electroencephalography (27 healthy subjects and 47 subjects with stable schizophrenia) were included., Results: PDE10A engagement by TAK-063 was verified with a novel PET radiotracer for use in primates and humans. TAK-063 showed favorable pharmacokinetic and safety profiles in humans, and TAK-063 reduced ketamine-induced changes in electroencephalography and BOLD signaling in animal models and healthy human subjects. In addition, analogous effects on cognition were observed in animal models and human subjects., Conclusions: Overall, the phase 1 results showed some consistent evidence of antipsychotic activity. This translational strategy may be valuable for the future development of novel therapeutic approaches, even when relevant nonclinical models are not available., (© The Author(s) 2020. Published by Oxford University Press on behalf of CINP.)

Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by inflammatory synovitis and progressive joint. Although the etiology is extremely complex, overwhelming evidence suggests that dysregulation or imbalance of the immune system plays a central role in disease pathogenesis. The bone loss and joint destruction are immunological insults mediated by infiltration and abnormal activation of various immune cells. Since pharmacological inhibition of cyclic nucleotide phosphodiesterases (PDEs), which degrade cyclic AMP and cyclic GMP, can regulate the activity of multiple immune cells, which are considered as a potential strategy for treating RA. Therefore, this review attempted to summarize the modulating effects of PDEs on immune cells and described the molecular underpinnings and potential clinical application of PDEs inhibitors for RA., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Aim: Phosphodiesterase 10A (PDE10A) inhibitors not only have antipsychotic-like effects but also cause cognitive enhancement without affecting extrapyramidal side effects in rodents, suggesting that PDE10A may be a novel approach for the treatment of schizophrenia. However, how a combination of PDE10A inhibitor with a currently available antipsychotic drug, risperidone contributes to the effect of each compound in rats remains unclear. The purpose of the present study was to examine the combination effects of MR1916 with a currently available antipsychotic drug, risperidone, in rats., Methods: We examined the combination effects of the PDE10A inhibitor, MR1916 with risperidone on conditioned avoidance response (CAR) to assess antipsychotic-like effects in rats. We also examined them on catalepsy as extrapyramidal side effects and novel object recognition test in cognitive functions in rats., Results: MR1916 (0.025-0.2 mg/kg, p.o.) and risperidone (0.75-6 mg/kg, p.o.) alone attenuated the CAR in a dose-dependent manner. The combination of MR1916 (0.025 mg/kg, p.o.) with risperidone (0.75 mg/kg, p.o.) significantly enhanced the attenuation of CAR without increasing the escape failure response. At the same dosage, the cataleptic effects were not enhanced by combined treatment of MR1916 with risperidone. Furthermore, the enhancement of object recognition memory induced by MR1916 (0.3 mg/kg, p.o.) was not affected by the combination with risperidone (0.75 mg/kg, p.o.)., Conclusion: The combination of MR1916 with risperidone may have additive antipsychotic-like effects without affecting extrapyramidal side effects, and the cognitive-enhancing effect of MR1916 may not be interfered with the addition of risperidone., (© 2020 Mochida Pharmaceutical Co., Ltd. Neuropsychopharmacology Reports published by John Wiley & Sons Australia, Ltd on behalf of The Japanese Society of Neuropsycho Pharmacology.)

There is conflicting results on whether prior antiplatelet therapy (APT) is associated with poor outcome in spontaneous intracerebral haemorrhage (ICH) patients. To determine whether prior APT is associated with spontaneous ICH, and whether there is a difference between the different types of APT, including cyclooxygenase inhibitor (COX-I), adenosine diphosphate receptor inhibitor (ADP-I) and phosphodiesterase inhibitor (PDE-I). A retrospective study of patients with ICH diagnosed between 2001 and 2013 in the National Health Insurance Research Database. Baseline unbalance between APT and non-APT groups was solved by multivariable adjustment (primary analysis) and propensity score matching (sensitivity analysis). Patients with prior APT had a higher rate of in-hospital death (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.09-1.23) compared to non-APT group. Compared to non-APT group, there was a greater rate of in-hospital death with spontaneous ICH with ADP-I (OR, 1.49; 95% CI, 1.24-1.79) and COX-I (OR, 1.17; 95% CI, 1.09-1.25). PDE-I exhibited no difference in in-hospital death with spontaneous ICH (OR, 1.03; 95% CI, 0.91-1.16) compared to non-APT group. Remarkably, the in-hospital mortality rate was significantly higher in the ADP-I group than in the PDE-I group (hazard ratio, 1.45; 95% CI, 1.17-1.80). In this study, ADP-I and COX-1, but not PDE-I, are the most likely contributors to the association of APT with poor outcome with spontaneous ICH patients. These findings suggest that the complexity of the different mechanism of actions of prior APT can alter the outcome in spontaneous ICH.

Acute heart failure (HF) and in particular, cardiogenic shock are associated with high morbidity and mortality. A therapeutic dilemma is that the use of positive inotropic agents, such as catecholamines or phosphodiesterase-inhibitors, is associated with increased mortality. Newer drugs, such as levosimendan or omecamtiv mecarbil, target sarcomeres to improve systolic function putatively without elevating intracellular Ca2+. Although meta-analyses of smaller trials suggested that levosimendan is associated with a better outcome than dobutamine, larger comparative trials failed to confirm this observation. For omecamtiv mecarbil, Phase II clinical trials suggest a favourable haemodynamic profile in patients with acute and chronic HF, and a Phase III morbidity/mortality trial in patients with chronic HF has recently begun. Here, we review the pathophysiological basis of systolic dysfunction in patients with HF and the mechanisms through which different inotropic agents improve cardiac function. Since adenosine triphosphate and reactive oxygen species production in mitochondria are intimately linked to the processes of excitation-contraction coupling, we also discuss the impact of inotropic agents on mitochondrial bioenergetics and redox regulation. Therefore, this position paper should help identify novel targets for treatments that could not only safely improve systolic and diastolic function acutely, but potentially also myocardial structure and function over a longer-term., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.)

The purpose of this study was to assess the impact of pentoxifylline and vitamin E on the incidence and severity of radiotherapy-induced oral mucositis and dysphagia in head and neck cancer patients. This is a prospective, randomized, controlled study. Head and neck cancer patients receiving 30-35 radiotherapy fractions with or without concurrent chemotherapy excluding those intolerant to xanthines, with any bleeding tendency were included. Sixty patients were enrolled; 30 patients received radiotherapy (control group) and 30 patients received radiotherapy with pentoxifylline and vitamin E (intervention group). The incidence, severity, onset and duration of oral mucositis and/or dysphagia were assessed. Locoregional control, quality of life, need for hospitalization, radiotherapy breaks, and adverse events were recorded and compared between groups. Pentoxifylline and vitamin E combination did not affect the incidence or the onset of oral mucositis or dysphagia. After adjusting for age, the combination reduced the incidence of severe oral mucositis (p = 0.01) and dysphagia (p = 0.012). The combination decreased the duration of oral mucositis and dysphagia by 5 weeks (p = 0.002) and 4 weeks (p = 0.003), respectively. The study drugs reduced the need for hospitalization (p = 0.002) and for radiotherapy breaks (p = 0.002) with improvement of FOIS (p = 0.014), EQ-5D index (p = 0.009) and VAS score (p = 0.012). Pentoxifylline and vitamin E decreased the occurrence of dysgeusia (p = 0.026) and fatigue (p = 0.026) without compromising locoregional control. Pentoxifylline/vitamin E combination reduced the severity and duration of acute radiotherapy-induced oral mucositis and dysphagia in head and neck cancer patients.Trial registry ClinicalTrials.gov registration number: NCT02397486.

Background: Current treatments for psychotic symptoms associated with schizophrenia often provide inadequate efficacy with unacceptable adverse effects. Improved therapeutics have long been a goal of research. Preclinical testing suggests that phosphodiesterase 10A (PDE10A) inhibitors may provide a novel approach to treating psychosis associated with schizophrenia., Methods: The efficacy and safety of a highly selective PDE10A inhibitor, PF-02545920, was evaluated in a phase 2 multicenter, randomized, double-blind, placebo-controlled, parallel-group study. Eligible patients (18-65 years) with an acute exacerbation of schizophrenia were randomized 2:2:1:2 to PF-02545920 (5 or 15 mg every 12 hours [Q12H] titrated), risperidone (3 mg Q12H), or placebo for 28 days (n = 74:74:37:74). The primary objectives were to evaluate the efficacy of PF-02545920 using the Positive and Negative Syndrome Scale (PANNS) and safety/tolerability., Results: At day 28, PF-02545920 (either dose) was not significantly different from placebo for mean change from baseline in the PANNS total score (primary end point) or most other end points. Pharmacokinetics exposures seemed adequate for binding/inhibiting PDE10A enzyme. Risperidone was statistically different from placebo for the PANNS total score, demonstrating study sensitivity. Incidence rates for adverse events were similar among the groups. Both doses of PF-02545920 were generally well tolerated. Dystonia occurred in 1, 6, 0, and 3 patients in the PF-02545920 5 mg Q12H, PF-02545920 15 mg Q12H, risperidone, and placebo groups, respectively., Conclusions: Neither dose of PF-02545920 was superior to placebo for the primary and most secondary end points. This indicates that PDE10A inhibition does not produce an antipsychotic effect in patients with acute exacerbation of schizophrenia.

Background: Pentoxifylline could reduce proteinuria and slow renal disease progression. We previously conducted a single-blind, randomized, controlled trial that showed that pentoxifylline decreases inflammatory markers and stabilizes renal function., Setting and Participants: 91 participants (46 in the pentoxifylline group and 45 in the control group) followed up for 7 additional years., Study Design: Post hoc analysis of a long-term follow-up after completion of the 12-months trial., Intervention: Pentoxifylline treatment (400 mg/twice a day) or standard treatment., Outcome: Renal event (defined as starting dialysis therapy and/or doubling serum creatinine and/or ≥ 50% decrease in estimated glomerular filtration rate) and cardiovascular mortality., Results: During follow-up, a renal event was recorded in 24 patients from control group (13 initiated dialysis therapy and serum creatinine doubled in 11) and 11 patients from PTF group (7 initiated dialysis and serum creatinine doubled in 4) (log Rank: 5.822, p = 0.016). The possible protector effect of PTF was more significant in albuminuric patients and was independently of diabetes mellitus presence. Treatment with PTF reduced the renal events by 35% compared to the control group in a Cox model adjusted for diabetes mellitus, albuminuria and basal renal function (HR 0.65 (0.45-0.94), p = 0.022). Cardiovascular mortality was significantly reduced in PTF treatment (2 patients vs. 10 in control group) (log Rank 5.0977, p = 0.024). PTF treatment reduced cardiovascular mortality in 55% adjusted for diabetes mellitus and age (HR 0.45 (0.21-0.98), p = 0.044) (Table 3)., Limitations: Small sample size, single center, not double blind and post hoc follow-up analysis., Conclusions: Long-term treatment with pentoxifylline may slow the rate of progression of kidney disease and reduce cardiovascular risk.

Background: Alopecia areata (AA) is a common non-scarring autoimmune disease that affects hair-bearing areas. A variety of therapeutic options has been used for treating this disease such as corticosteroids, minoxidil, methotrexate, cyclosporine, and azathioprine. Intralesional triamcinolone acetonide (TRA) injection is considered the first-line treatment in localized alopecia areata involving <50% of the scalp; however, intralesional steroid injections are associated with a variety of side effects., Objective: The aim of this study was to evaluate the efficacy of pentoxifylline (PTX) vs triamcinolone acetonide intralesional in localized AA., Patients and Methods: The sample included 75 patients (47 males and 28 females) aged 18-55 years, diagnosed as localized alopecia areata. The patients were treated by intralesional injection every three weeks up to five sessions. The patients were classified into three groups according to the used therapeutic modality. Group A: 25 patients treated by intralesional injection of TRA. Group B: 25 patients treated by combined intralesional injection of TRA and PTX injection. Group C: 25 patients treated by intralesional PTX injection., Results: Both PTX and TRA intralesional injections were effective in the treatment of AA, but there was a statistically significant difference regarding the response to treatment between the three study groups (P value = 0.01). The highest response was reported in combined drug usage (TRA & PTX) followed by PTX alone and then TRA alone (72.0%, 60.0%, and 32.0%, respectively)., Conclusion: Pentoxifylline intralesional injection is effective, easy to perform with little side effects for the treatment of localized alopecia areata., (© 2018 Wiley Periodicals, Inc.)

Background: Patients with cognitive impairment associated with schizophrenia may benefit from treatments targeting dysfunctional glutamatergic neurotransmission. BI 409306, a potent and selective phosphodiesterase 9 inhibitor, was assessed in patients with schizophrenia using a learn-and-confirm adaptive trial design., Methods: This double-blind, parallel-group trial randomized patients 2:1:1:1:1 to once-daily placebo or BI 409306 (10, 25, 50, or 100 mg) for 12 weeks. Stage 1 (learn) assessed change from baseline in Cambridge Neuropsychological Test Automated Battery (CANTAB) scores (week 12) to identify ≥1 meaningful endpoints for stage 2 (confirm). If no domains showed efficacy, change from baseline in Measurements and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB) composite scores (week 12) was the primary endpoint. The key secondary endpoint was change from baseline in Schizophrenia Cognition Rating Scale (SCoRS) total score. Safety was monitored., Results: Five hundred eighteen patients were randomized. In stage 1, CANTAB did not differentiate between BI 409306 and placebo (n = 120), so the primary endpoint of change from baseline in MCCB composite score was analyzed in 450 patients in stage 2. There was no significant difference between BI 409306 (1.2-2.8) and placebo (2.5) in MCCB composite score change. BI 409306 did not significantly improve change from baseline in SCoRS total score (-3.1 to -2.0) vs placebo (-2.5). Adverse events were dose-dependent, increasing from 33.3% (10 mg) to 53.5% (100 mg), vs 36.4% for placebo., Conclusion: The primary endpoint of cognitive function improvement was not met. BI 409306 was well-tolerated, with an acceptable safety profile., (© The Author(s) 2018. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center.)

This phase Ib study randomized patients with stable sickle cell disease (SCD) aged 18-65 years to twice-daily PF-04447943 (a phosphodiesterase 9A inhibitor; 5 or 25 mg) or placebo, with/without hydroxyurea coadministration, for up to 29 days. Blood samples were collected at baseline and various posttreatment time points for assessments of PF-04447943 pharmacokinetics (PKs)/pharmacodynamics (PDs). Change from baseline in potential SCD-related biomarkers was evaluated. Of 30 patients, 15 received hydroxyurea and 28 completed the study. PF-04447943, with/without hydroxyurea, was generally well tolerated, with no treatment-related serious adverse events. Plasma PF-04447943 exposure was dose proportional. Twice-daily PF-04447943 25 mg significantly reduced the number and size of circulating monocyte-platelet and neutrophil-platelet aggregates and levels of circulating soluble E-selectin at day 29 vs. baseline (adjusted P < 0.15). PF-04447943 demonstrated PK/PD effects suggestive of inhibiting pathways that may contribute to vaso-occlusion. This study also provides guidance regarding biomarkers for future SCD studies., (© 2018 Pfizer Inc. Clinical and Translational Science published by Wiley Periodicals, Inc. on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Introduction: Severe, inadequately-controlled asthma remains a clinical challenge. For this reason, clinical trials and preclinical experimental studies on novel agents as an add-on therapies continue emerge. Phosphodiesterases (PDEs) are enzymes that regulate the function of immune cells by hydrolyzing cyclic guanosine monophosphate/cGMP and cyclic adenosine monophosphate/cAMP. PDEs are divided into subfamilies [PDE3, PDE4, PDE5 and PDE7] which are mainly found in the respiratory tract. Inhibitors of PDEs have already been approved for COPD and pulmonary hypertension., Areas Covered: The role of PDE inhibitors in asthma treatment and the possible mechanism of action via their anti-inflammatory and/or bronchodilating effect are discussed., Expert Opinion: Novel PDE inhibitors exhibiting fewer adverse events may have a role as add-on therapies in asthma treatment in the future. More clinical trials are necessary to prove their efficacy and evaluate their safety profile before approval by regulatory bodies is granted.

Introduction: The efficacy and safety of arginine supplements in erectile dysfunction (ED) remain debatable., Aim: To assess the potential role of arginine supplements on ED as alternatives to phosphodiesterase inhibitors., Methods: Studies published up to April 2018 that evaluated the efficacy of arginine supplements were identified from multiple databases (Google Scholar, PubMed, Medline, Embase, Kiss, DBpia, and Cochrane databases). Studies comparing arginine supplements with placebo or no treatment; focusing only on patients with mild to moderate severity of ED; and presenting outcomes such as improvement rate, International Index of Erectile Function (IIEF) score, and adverse effects were included. Subgroup analysis for arginine alone and arginine in combination with other substances was further conducted to increase interpretability., Main Outcome Measure: The strength of the association between arginine supplements and ED was assessed using relative odds ratios and weighted mean differences with 95% CI., Results: In total, 10 randomized controlled trials met the inclusion criteria, reporting the outcomes of 540 patients with ED. The analysis demonstrated that arginine supplements with dosage ranging from 1,500 to 5,000 mg significantly improved ED compared with placebo or no treatment (odds ratios, 3.37 [1.29, 8.77], P = .01, I2 = 44). Arginine supplements also caused significant improvements in the IIEF subdomain scores of overall satisfaction, intercourse satisfaction, orgasmic function, and erectile function, whereas the IIEF sexual desire score remain unchanged. The adverse effect rate in the arginine-treated group was 8.3%, and that in the placebo group was 2.3%, none of which were severe., Clinical Implications: Arginine supplements can be recommended to patients with mild to moderate ED., Strength & Limitations: The strength of this study is that it is the first meta-analysis to assess the potential role of arginine supplements in ED compared with placebo or no treatment. A limitation is that the treatment dosage and duration varied among studies, which may have contributed to study heterogeneity., Conclusion: The results of our systematic review and meta-analysis provide evidence on the effectiveness of arginine supplements for mild to moderate ED. Rhim HC, Kim MS, Park Y-J, et al. The Potential Role of Arginine Supplements on Erectile Dysfunction: A Systemic Review and Meta-Analysis. J Sex Med 2019;16:223-234., (Copyright © 2018 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.)

Introduction: TAK-063 is a potent, selective inhibitor of phosphodiesterase 10A, an enzyme selectively expressed in medium spiny neurons of the striatum. This randomized, parallel-group study evaluated the efficacy and safety of 20-mg daily TAK-063 versus placebo in subjects with acutely exacerbated symptoms of schizophrenia (NCT02477020)., Methods: Adults aged 18 to 65 with diagnosed schizophrenia and psychotic symptoms that exacerbated within 60 days before screening were included. Subjects who discontinued psychotropic medications before screening were randomized 1:1 to 6 weeks of placebo (n = 81) or 20-mg TAK-063 (n = 83). Weekly efficacy visits were conducted during the treatment period, and dose de-escalation was allowed (blinded) to 10-mg TAK-063 for intolerability., Results: The primary endpoint, change from baseline in the Positive and Negative Syndrome Scale total score at week 6, was not achieved (least-squares mean difference vs placebo [standard error] = -5.46 [3.44]; p = 0.115). Secondary endpoints were generally supportive of antipsychotic efficacy. Consistent with previous phase 1 studies, TAK-063 was safe and well tolerated, and most adverse events were mild or moderate in severity and did not result in discontinuation. No deaths occurred, and the incidence of akathisia and dystonia, categories of extrapyramidal syndromes, was more frequent in the TAK-063 group than placebo., Conclusions: Although the study did not meet the primary endpoint (effect size = 0.308), the effects of TAK-063 on the primary and secondary endpoints may be suggestive of antipsychotic activity. Interpretation of these results is confounded by a relatively high placebo effect and a lack of dose-ranging or active reference., (Copyright © 2018. Published by Elsevier B.V.)

Objective: To investigate the effect of the pre-administration with aminophylline on the occurrence of post-dural puncture headache (PDPH) in women undergoing caesarean section by combined spinal-epidural anaesthesia (CSEA)., Methods: The study enrolled women undergoing elective caesarean sections with CSEA and randomly allocated them into two groups; for 30 min immediately after the infant was delivered, group A received 250 mg aminophylline intravenously and group B received an equal volume of normal saline. Demographic data, operation time, intraoperative blood loss, intraoperative transfusion volume and the occurrence of PDPH during the first 7 days after the operation were recorded. Side-effects such as hypersensitivity, convulsion and arrhythmia were also recorded in the patients and infants in group A within 24 h after aminophylline administration., Results: A total of 120 patients aged 24-38 years (pregnancy range, 38-42 weeks) were randomly allocated into two groups ( n = 60). The incidence of PDPH in group A was significantly lower than group C (two of 59 [3.4%] versus 10 of 58 [17.2%], respectively). There were no related side-effects within 24 h after aminophylline administration in group A., Conclusions: Intraoperative intravenous infusion of 250 mg aminophylline reduced the incidence of PDPH after caesarean section under CSEA with no side-effects.

The goal of this study was to investigate the effect of different phosphodiesterase inhibitors (PDEIs), on renal oxidant/antioxidant balance in diabetic rats. Our study was conducted on 125 rats, diabetes was induced in 100 rats by a single administration of streptozocin (STZ). Diabetic rats were divided into four equal groups. The first group was assigned as diabetic control, the remaining three groups were treated with pentoxifylline, sildenafil and milrinone via drinking water for 15 successive days, another group of 25 normal rats was assigned as non-diabetic control. Significant increase in plasma levels of glucose, urea, creatinine, malondialdehyde (MDA), and nitric oxide (NO) with a concomitant decrease in the levels of insulin, reduced glutathione (GSH), glutathione peroxidase (Gpx), superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (TAC) were observed in diabetic rats. These alterations were reverted back to near normal level after treatment with PDEIs. Our data seem to suggest a potential role of PDEIs in maintaining health in diabetes by reducing the progression of diabetic nephropathy.

Background: Benign prostatic hyperplasia (BPH) refers to non-malignant enlargement of the prostate gland that may cause bothersome lower urinary tract symptoms (LUTS). Alpha-blockers (ABs) and 5-alpha reductase inhibitors (5-ARIs) are the mainstay of medical treatment. Recently, phosphodiesterase inhibitors (PDEIs) that so far have been used mainly to treat erectile dysfunction were introduced to treat male LUTS., Objectives: To assess the effects of PDEIs compared to placebo and other standard of care drugs (ABs and 5-ARIs) in men with LUTS consistent with BPH., Search Methods: We conducted a systematic search of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Web of Science, and clinical trials registries of the World Health Organization (WHO) and the National Institutes of Health (NIH) (updated 2 August 2018). We performed citation tracking and handsearching of abstracts and conference proceedings. We also contacted study authors to ask for additional information., Selection Criteria: We considered for inclusion in this systematic review randomised controlled trials (RCTs) comparing PDEIs versus placebo, ABs, or 5-ARIs for at least four weeks in men with BPH-LUTS., Data Collection and Analysis: Three review authors independently screened the literature and extracted data. Primary outcomes were effects on urinary symptoms as assessed by the International Prostate Symptom Score (IPSS-total; score ranging from 0 to 35, with higher values reflecting more symptoms), urinary bother as assessed by the Benign Prostatic Hyperplasia Impact Index (BPHII; score ranging from 0 to 13, with higher values reflecting more bother), and adverse events (AEs). We used GRADE to rate the quality of evidence. We considered short-term (up to 12 weeks) and long-term (12 weeks or longer) results separately., Main Results: We included a total of 16 randomised trials in this review. The results for primary outcomes are as follows.PDEI versus placebo: PDEIs may result in a small improvement in IPSS-total score (mean difference (MD) 1.89 lower, 95% confidence interval (CI) 2.27 lower to 1.50 lower; n = 4293; low-quality evidence) compared to placebo, and may reduce the BPHII score slightly (MD 0.52 lower, 95% CI 0.71 lower to 0.33 lower; n = 3646; low-quality evidence). Rates of AEs may be increased (risk ratio (RR) 1.42, 95% CI 1.21 to 1.67; n = 4386; low-quality evidence). This corresponds to 95 more AEs per 1000 participants (95% CI 47 more to 151 more per 1000). Study results were limited to a treatment duration of six to 12 weeks.PDEI versus AB: PDEIs and ABs probably provide similar improvement in IPSS-total score (MD 0.22 higher, 95% CI 0.49 lower to 0.93 higher; n = 933; moderate-quality evidence) and may have a similar effect on BPHII score (MD 0.03 higher, 95% CI 1.10 lower to 1.16 higher; n = 550; low-quality evidence) and AEs (RR 1.35, 95% CI 0.80 to 2.30; n = 936; low-quality evidence). This corresponds to 71 more AEs per 1000 participants (95% CI 41 fewer to 264 more per 1000). Study results were limited to a treatment duration of six to 12 weeks.PDEI and AB versus AB alone: the combination of PDEI and AB may provide a small improvement in IPSS-total score (MD 2.56 lower, 95% CI 3.92 lower to 1.19 lower; n = 193; low-quality evidence) compared to AB alone. We found no evidence for BPHII scores. AEs may be increased (RR 2.81, 95% CI 1.53 to 5.17; n = 194; moderate-quality evidence). This corresponds to 235 more AEs per 1000 participants (95% CI 69 more to 542 more per 1000). Study results were limited to treatment duration of four to 12 weeks.PDEI and AB versus PDEI alone: the combination of PDEI and AB may provide a small improvement in IPSS-total (MD 2.4 lower, 95% CI 6.47 lower to 1.67 higher; n = 40; low-quality evidence) compared to PDEI alone. We found no data on BPHII or AEs. Study results were limited to a treatment duration of four weeks.PDEI and 5-ARI versus 5-ARI alone: in the short term (up to 12 weeks), the combination of PDEI and 5-ARI probably results in a small improvement in IPSS-total score (MD 1.40 lower, 95% CI 2.24 lower to 0.56 lower; n = 695; moderate-quality evidence) compared to 5-ARI alone. We found no evidence on BPHII scores or AEs. In the long term (13 to 26 weeks), the combination of PDEI and 5-ARI likely results in a small reduction in IPSS-total score (MD 1.00 less, 95% CI 1.83 lower to 0.17 lower; n = 695; moderate-quality evidence). We found no evidence about effects on BPHII scores. There may be no difference in rates of AEs (RR 1.07, 95% CI 0.84 to 1.36; n = 695; low-quality evidence). This corresponds to 19 more AEs per 1000 participants (95% CI 43 fewer to 98 more per 1000).We found no trials comparing other combinations of treatments or comparing different PDEI agents., Authors' Conclusions: Compared to placebo, PDEI likely leads to a small reduction in IPSS-total and BPHII sores, with a possible increase in AEs. There may be no differences between PDEI and AB with regards to improvement in IPSS-total, BPHII, and incidence of AEs. There appears to be no added benefit of PDEI combined with AB compared to PDEI or AB alone or PDEI combined with 5-ARI compared to ARI alone with regards to urinary symptoms. Most evidence was limited to short-term treatment up to 12 weeks and of moderate or low certainty.

Background: There are limited treatments for progressive multiple sclerosis. Ibudilast inhibits several cyclic nucleotide phosphodiesterases, macrophage migration inhibitory factor, and toll-like receptor 4 and can cross the blood-brain barrier, with potential salutary effects in progressive multiple sclerosis., Methods: We enrolled patients with primary or secondary progressive multiple sclerosis in a phase 2 randomized trial of oral ibudilast (≤100 mg daily) or placebo for 96 weeks. The primary efficacy end point was the rate of brain atrophy, as measured by the brain parenchymal fraction (brain size relative to the volume of the outer surface contour of the brain). Major secondary end points included the change in the pyramidal tracts on diffusion tensor imaging, the magnetization transfer ratio in normal-appearing brain tissue, the thickness of the retinal nerve-fiber layer, and cortical atrophy, all measures of tissue damage in multiple sclerosis., Results: Of 255 patients who underwent randomization, 129 were assigned to ibudilast and 126 to placebo. A total of 53% of the patients in the ibudilast group and 52% of those in the placebo group had primary progressive disease; the others had secondary progressive disease. The rate of change in the brain parenchymal fraction was -0.0010 per year with ibudilast and -0.0019 per year with placebo (difference, 0.0009; 95% confidence interval, 0.00004 to 0.0017; P=0.04), which represents approximately 2.5 ml less brain-tissue loss with ibudilast over a period of 96 weeks. Adverse events with ibudilast included gastrointestinal symptoms, headache, and depression., Conclusions: In a phase 2 trial involving patients with progressive multiple sclerosis, ibudilast was associated with slower progression of brain atrophy than placebo but was associated with higher rates of gastrointestinal side effects, headache, and depression. (Funded by the National Institute of Neurological Disorders and Stroke and others; NN102/SPRINT-MS ClinicalTrials.gov number, NCT01982942 .).

Although inhaled therapies are typically preferred for the maintenance treatment of obstructive lung diseases, oral drug therapies can also play valuable roles. The most commonly used oral agents are phosphodiesterase inhibitors, theophylline, macrolides, leukotriene modifiers, and mucoactive agents. Advantages of these oral agents include the unique pharmacologic mechanisms of action, the avoidance of the challenges of proper inhalational lung administration, and, in most instances, relative drug cost. For many of these agents, anti-inflammatory or immunomodulatory effects are the predominant pharmacologic mechanism that each provides clinical benefit, with the exception of guaifenesin. In addition, theophylline, leukotriene modifiers, chronic macrolides, phosphodiesterase inhibitors, and N-acetylcysteine have been shown to decrease exacerbations in obstructive lung disease. Fairly rapid bronchodilation occurs with the phosphodiesterase inhibitors, theophylline, and leukotriene modifiers, although less than that achieved with inhaled therapies. The clinical roles of phosphodiesterase inhibitors, specifically roflumilast, and macrolides continues to be defined today, whereas the roles theophylline and leukotriene modifiers have probably been largely delineated. Azithromycin is the principal macrolide used chronically for obstructive lung diseases, especially COPD. Although guaifenesin is used widely, its effectiveness is unclear, whereas N-acetylcysteine currently has strong evidence supporting a decreased risk of COPD exacerbations. Mucolytic agents like N-acetylcysteine are used more widely outside the United States in obstructive lung diseases., (Copyright © 2018 by Daedalus Enterprises.)

Safety, tolerability and pharmacokinetics of BI 409306, a potent and selective phosphodiesterase 9A inhibitor, were assessed in healthy subjects in three Phase I, within-dose group, double-blind trials. Trial 1 randomised young and elderly subjects to receive BI 409306 25, 50, 100 mg, placebo once daily (OD) or BI 409306 50 mg twice daily (young) for 14 days. Trial 2 randomised young poor metabolisers (PM) of cytochrome P450 isoform 2C19 (CYP2C19) and elderly subjects to receive BI 409306 25, 50 mg or placebo OD for 14 days. Trial 3 randomised Chinese and Japanese extensive metabolisers of CYP2C19 to receive single doses (SD) of BI 409306 25, 50, 100 mg or placebo and Chinese (PM) to SD of BI 409306 100 mg or placebo (Part 1). Japanese PM received SD of BI 409306 100 mg or placebo (Day 1) followed by BI 409306 100 mg or placebo OD for 7 days after a 48-hour washout period (Part 2). Reported adverse events (AE) were mild-to-moderate intensity and increased with BI 409306 dose. Eye disorders were most commonly reported (Trial 1: 40.0-41.7%, Trial 2: 29.2-37.5%, Trial 3: 18.2-66.7%) and increased with dose and systemic exposure. PM reported more AEs than other treatment groups, corresponding to higher systemic exposure to BI 409306. Systemic exposure to BI 409306 produced dose-dependent increases and was slightly greater in elderly versus young subgroups (Trial 1). Steady state was achieved by Day 2-3. Overall, BI 409306 demonstrated good safety, tolerability and minor accumulation after multiple dosing., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)

A fixed-dose combination tablet of benazepril and pimobendan (Fortekor Plus; Elanco Animal Health) was tested in dogs with congestive heart failure (CHF) caused by myxomatous mitral valve disease (MMVD) in a three-arm, masked, randomized, non-inferiority clinical trial in Japan. The test group (n = 34) received Fortekor Plus twice daily. Two control groups received registered formulations of benazepril (Fortekor; Elanco Animal Health) and pimobendan (Vetmedin; Boehringer Ingelheim Vetmedica) with administration of Vetmedin twice daily and Fortekor twice (Control I, n = 14) or once (Control II, n = 19) daily. Diuretics were used in 22 dogs (32.8%). Global clinical scores decreased significantly from baseline in all groups; there were no significant differences between groups, and non-inferiority of Fortekor Plus compared to Control I, Control II, and combined Control I + II groups was demonstrated. There were no significant differences between groups for relevant clinical chemistry and hematology variables or frequency of all adverse events. Frequency of emesis was significantly ( p = 0.0042) lower in the Fortekor Plus (8.8%) group than in the Control I + II (39.4%) group. In conclusion, Fortekor Plus had non-inferior efficacy and was associated with significantly less emesis compared to Fortekor and Vetmedin in dogs with CHF caused by MMVD.

Background: Sexual dysfunction affects millions of people with an increasing prevalence, worldwide. The pathophysiology of the disease shares several similarities with cardiovascular disease (CVD), including atherosclerosis, endothelial dysfunction, structural vascular damage and subclinical inflammation. Erectile dysfunction (ED) and female sexual dysfunction are common among patients with CVD and risk factors such as hypertension, diabetes, obesity and metabolic syndrome. Given the common pathogenesis of the diseases, ED is an independent prognostic factor of future ED events. Patients with overt ED or risk factors are usually treated with several drugs for the management of these conditions. Several of these drugs have been evaluated for their effect on sexual activity., Results and Conclusion: Among the antihypertensive drugs, diuretics and beta-blockers seem to exert a detrimental impact on sexual function, with nebivolol being the only beta-blocker with favorable properties through an increase in nitric oxide bioavailability. In contrast, renin-angiotensin system inhibitors and calcium-channel blockers have a neutral effect on sexual activity. Hypoglycemic drugs have been less evaluated in the ED setting, with metformin, pioglitazone and liraglutide presenting favorable results. Statins on the other hand have not provided consistent results with observational studies suggesting a detrimental role in sexual activity and a few randomized studies indicating a neutral or even beneficial effect on erectile function., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Background: There is evidence for an association between major depressive disorder (MDD) and both inflammatory and phosphodiesterase (PDE) pathways. This study aimed to evaluate the adjunct role of the PDE inhibitor pentoxifylline (PTX), a compound with anti-inflammatory properties, in the treatment of adult patients with MDD., Methods: This was a prospective, 12-week, double-blind study of parallel groups. Eighty adult outpatients who met the DSM-IV criteria for MDD participated in the trial. Patients were required to have a baseline Hamilton Rating Scale for Depression (HAM-D) score of at least 18. Patients were allocated randomly: 40 received escitalopram 20 mg/day plus placebo while the other 40 received escitalopram 20 mg/day plus PTX (400 mg b.i.d.). Patients were assessed by a psychiatrist at baseline, and 4, 8, and 12 weeks after the medication had been started. The serum levels of TNF-α, IL-6, IL-10, BDNF, 8-OHdG, and serotonin were measured at baseline and after therapy., Results: After 8 and 12 weeks, the PTX group showed a statistically significantly greater improvement in HAM-D score compared to the control group (least squares mean difference [LSMD] -3.29, p = 0.000 and LSMD -3.49, p = 0.000, respectively). Moreover, the PTX group showed a statistically significantly greater reduction in the serum levels of TNF-α, IL-6, IL-10, and 8-OHdG along with a statistically significant increase in the levels of BDNF and serotonin in comparison with the control group after the treatment., Conclusion: The findings of this study suggest that PTX could be a promising adjunct to antidepressants in the treatment of MDD patients., (© 2018 S. Karger AG, Basel.)

Background: Phosphodiesterase 10A (PDE10A) is selectively expressed in medium spiny neurons of the striatum. TAK-063 is a selective inhibitor of PDE10A in clinical development for the treatment of schizophrenia., Objectives: Safety, tolerability, and pharmacokinetics (PK) of TAK-063 were evaluated following multiple rising oral doses, and PK/adverse event (AE) models were developed to characterize the relationship between TAK-063 exposure and incidence of specific AEs., Methods: Healthy Japanese subjects (HJS) aged 20-55 years and subjects with stable schizophrenia (SSS) aged 18-55 years were enrolled and randomized to either TAK-063 or placebo. Study medication was administered as a tablet once daily (at night) with food over a 7-day period., Results: TAK-063 and placebo groups consisted of 62 and 15 subjects, respectively. A majority of subjects (71 of 77) completed the study. AEs were mostly of mild or moderate severity, and no deaths were reported. The most common AE was somnolence. For equivalent doses, the rate of extrapyramidal syndromes (EPS) was higher in SSS than in HJS. PK parameters were comparable between HJS and SSS at equivalent doses. The incidence of somnolence and EPS symptoms increased with exposure, and this was described with the PK/AE model. A maximum tolerated dose was not determined., Conclusions: Multiple doses of TAK-063 were safe and well tolerated. PK/AE models characterized the incidence of somnolence and EPS with increasing TAK-063 exposure, and simulations suggested that a once-daily dose range of up to 30 mg would be suitable for future studies. CLINICALTRIALS., Gov Identifier: NCT01879722.

Objective: To compare different support therapies in very low birth-weight preterm neonates with nosocomial sepsis., Methods: This clinical pilot study was conducted at the Bagcilar Research and Training Hospital, Istanbul, Turkey, from September 2015 to November 2016. Preterm infants appropriately sized for a gestational age of < 32 weeks and < 1,500g were included in the study. Pentaglobin was initiated on the day of diagnosis of nosocomial sepsis to very low birth-weight preterm neonates as a support therapy in addition to antibiotics: 5 ml/kg per day of pentaglobin was infused over a four-hour period on three consecutive days. Pentoxifylline (5 mg/kg every 6 hours) was administered to premature infants with sepsis on three successive days., Results: Of the 41 neonates, 19(46.3%) were girls and 22(53.7%) were boys. Vital signs, haematologic tables, peripheral blood smear left shift ratio, and blood-gas parameters did not differ significantly between the groups (p>0.05), but the C-reactive protein (mg/dl) values significantly decreased after pentoxifylline treatment (p<0.05). Coagulase-negative staphylococci were the most frequently isolated bacteria in the two groups (n=4; 19% vs. n=4; 20%). There was no difference in isolated microorganisms. There was no significant difference in intraventricular haemorrhage, necrotising enterocolitis, periventricular leukomalacia or symptomatic patent ductus arteriosus in the neonates when comparing the two groups and no systemic reactions were observed during adjuvant therapy in the preterm neonates (p>0.05). The total duration of hospitalisation was 49.46±13.52 days for the pentaglobin group and 44.21±11.1 days for the pentoxifylline group neonates., Conclusions: Pentoxifylline treatment for nosocomial sepsis decreased C-reactive protein levels and heart rate more than pentaglobin therapy.

Introduction: Phosphodiesterase (PDE) inhibitors improve signaling pathways in brain circuits by increasing intracellular cyclic adenosine monophosphate (cAMP) and/or cyclic guanosine monophosphate (cGMP). In the last decade, the first clinical studies investigating selective PDE inhibitors in Alzheimer's disease (AD) have been initiated, based on their positive effects on cognitive processes and neuroprotection in numerous animal studies. Areas covered: This article reviews the clinical studies investigating the pro-cognitive/neuroprotective effects of PDE inhibitors in patients with AD, as well as in age-associated memory impaired elderly and patients with mild cognitive impairment (MCI), the prodromal stage of AD. PDE inhibitors will also be discussed with respect to adverse effects including safety and tolerability. Expert opinion: The limited available data of clinical studies with PDE inhibitors tested in different populations of AD patients do not allow the drawing of any concrete conclusion yet. Currently, studies with a PDE3 (cilostazol) or PDE9 inhibitor (BI 409,306) are still ongoing in patients with MCI or AD, respectively. Studies with PDE4 inhibitors (HT-0712, roflumilast and BPN14770) in healthy elderly and elderly with age-associated memory impairments indicate that the optimum dose and/or inhibiting the most relevant PDE isoform hold great promise when tested in the appropriate population of patients with MCI or AD eventually.

Background: Peyronie's disease is a relatively common condition in urological practice, but is still poorly identified and understood in the wider medical community and by most of the public. Identifying the condition and appropriate referral for expert opinion can significantly lessen the physical and psychological effect on patients., Objective: The objective of this article is to provide general practitioners with a concise and updated review of Peyronie's disease, with the aim of helping them to provide appropriate advice to their patients., Discussion: Peyronie's disease is an aberrant wound healing process culminating in excess scar formation in the penis, which may cause penile pain, shortening and curvature. It is often accompanied by erectile dysfunction, and can result in progressive and severe impairment of penetrative intercourse. The course of the disorder is divided into active inflammatory and chronic stable phases. Oral therapy is usually of limited efficacy, while penile traction may only be beneficial in motivated patients. Intralesional injections of collagenase were recently introduced as a non-surgical measure to decrease penile curvature. Surgery remains the most effective treatment for Peyronie's disease and is considered the gold standard.

Objective: While decreased ocular blood flow is thought to be a possible contributor to glaucoma pathogenesis, it is unclear what role systemic phosphodiesterase inhibitors (PDEi) play. We performed a cross-sectional study of a nationally representative sample of the U.S. population to investigate the relationship between the most commonly used PDEi, sildenafil and theophylline, and self-reported glaucoma., Methods: We used the National Health and Nutrition Examination Survey 2005-2008 cycles for this observational study. 7,042 participants, aged 40 years and over, responded to a survey item on glaucoma status and were included in the analysis. Multivariable logistic regression models were constructed to evaluate the association between at least 1 year of self-reported PDEi use and prevalent glaucoma. Regressions were adjusted for potential confounding variables, including demographics, socioeconomic status, and general health conditions, and accounted for the complex design of the survey. Sample weights were constructed and used to ensure the generalizability of results., Results: 482 respondents self-reported a diagnosis of glaucoma, of which 11 used sildenafil and 20 used theophylline for at least 1 year. Covariates significantly associated with higher odds of glaucoma prevalence in univariable analyses included older age, black race, former smoking status, diabetes, hyperlipidemia, myocardial infarction, and stroke. Conversely, higher education and income were significantly associated with lower odds of glaucoma prevalence. In regression analyses adjusted for demographic and socioeconomic variables, sildenafil (OR = 4.90, CI: 1.24-19.27, p = 0.025) and theophylline (OR = 3.15, CI: 1.46-6.80, p = 0.005) were significantly associated with higher odds of self-reported glaucoma. These associations held after further adjustment with general health behaviors and conditions for both sildenafil and theophylline., Conclusions: Use of sildenafil and theophylline for one or more years was associated with greater prevalence of self-reported glaucoma, a finding which requires further prospective study to assess causality and possible mechanisms of action.

Objective  The objective of this study was to assess the result of intravenous pentoxifylline as an adjunct to antibiotic therapy on mortality and morbidity in very low birth weight (VLBW) preterm neonates with nosocomial sepsis. Methods  For the 18 VLBW preterm neonates, as an adjunct therapy to antibiotics regimens, pentoxifylline (5 mg/kg/h for 6 hours) was administered to premature infants with sepsis on 3 successive days. Clinical and laboratory parameters were recorded before and after treatment. Results  Following pentoxifylline therapy, the immature-to-total neutrophil ratio and C-reactive protein (CRP) levels were significantly decreased, while the blood pH and base excess were significantly increased ( p  < 0.05). The axillary temperature, noninvasive blood pressure, hemoglobin, leukocyte, and thrombocyte values did not significantly differ after treatment ( p  > 0.05). Coagulase-negative staphylococci (CoNS) (32%), Streptococcus hominis (7.3%), Pseudomonas aeruginosa (5.3%), and Candida parapsilosis (3.1%) were identified in the blood cultures. There were no short-term morbidities (intraventricular hemorrhages, necrotizing enterocolitis, periventricular leukomalacia, and patent ductus arteriosus), no adverse effects, and no mortalities during or after the pentoxifylline therapy in the preterm neonate participants. Conclusion  The CRP levels and heart rate both decreased, while the pH and base excess parameters of the blood gas analysis changed positively after pentoxifylline treatment in VLBW preterm neonates with nosocomial sepsis., Competing Interests: Conflict of Interest: None., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Atopic dermatitis (AD) is an extremely common condition affecting as many as 10-20% of children and 2-10% of adults. A particularly distressing symptom of AD is pruritus. One of the important aspects of AD is inflammation associated with increased activity of phosphodiesterase 4 (PDE4), resulting in decreased intracellular levels of cyclic adenosine monophosphate, which in turn causes increased production of inflammatory cytokines. Crisaborole was developed as a small-molecule, boron-based, selective PDE4 inhibitor that can be used topically. Clinical trials have demonstrated its efficacy in treating patients with mild to moderate AD, resulting in significant relief of pruritus. Unlike PDE4 inhibitors that act systemically, crisaborole does not cause significant gastrointestinal adverse effects. The most common adverse effect has been temporary stinging and burning in about 4% of patients upon application of the 2% ointment. To date there is no evidence of atrophy, telangiectasia or hypopigmentation resulting from its use. Crisaborole is the first topically applied PDE4 inhibitor to be approved by the FDA for use in AD., (Copyright 2017 Clarivate Analytics.)

Aims: The aim of the present study was to investigate the safety, tolerability, dose proportionality and relative bioavailability of tablet and oral solution formulations of BI 409306 in healthy male subjects, and to compare the safety and pharmacokinetics in subjects who were extensive metabolizers (EMs) or poor metabolizers (PMs) of cytochrome P450 (CYP)-2C19., Methods: The present randomized, double-blind, placebo-controlled, single-centre study evaluated single rising doses of BI 409306 (0.5-500 mg) administered as a tablet or oral solution to EMs or PMs., Results: Of 80 enrolled subjects (mean age 36.7 years), 79 (CYP2C19 EMs, 71; CYP2C19 PMs, eight) received treatment and completed the study. Adverse events (AEs) were mild to moderate in intensity. Overall, 17/71 (23.9%) EMs and 6/8 (75.0%) PMs experienced 28 and eight AEs, respectively, of which, 25 and seven AEs, respectively, were considered to be drug related. The most frequently reported AEs were nervous system and eye disorders; all occurred shortly (20-30 min) after administration and mostly resolved within 1-2 h. No serious AEs occurred. BI 409306 systemic absorption and elimination were rapid; peak plasma concentration (C max ) was reached <1 h after drug administration, and the half-life ranged from 0.99 h to 2.71 h. Both the tablet and oral solution resulted in similar exposures. In PMs, at dose levels of 10 mg and 100 mg, C max was 2.2-2.3-fold higher, and the area under the plasma concentration-time curve over the time interval 0 extrapolated to infinity was 4.1-5.0-fold higher compared with EMs., Conclusions: In healthy male subjects, BI 409306 was generally safe and well tolerated, with rapid absorption and elimination. Systemic exposure was higher in CYP2C19 PMs than EMs at the same dose level., (© 2016 Boehringer Ingelheim. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Background: Phosphodiesterase-5 (PDE-5) inhibitors enhance penile erection and have gained popularity not only for erectile dysfunction, but also in recreational settings. Nevertheless, adverse effects have been associated with their use, with nasal bleeding among them. PDE-5 inhibitor action is materialized through the inhibition of the cyclic guanosine monophosphate (cGMP) enzyme. cGMP is present at several sites of the human body in addition to the corpus cavernosum, leading to the adverse effects associated with its nonselective inhibition., Case Reports: Two male patients with severe epistaxis who were taking PDE-5 inhibitors for erectile dysfunction or recreational purposes are discussed. Surgical intervention was required in both patients to control the nasal hemorrhage. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Nasal bleeding in patients who are taking PDE-5 inhibitors might represent an under-reported cause of epistaxis because of the unwillingness of most male patients to discuss issues pertaining their use without hesitation. Yet such episodes are rather profuse. This is especially true when the venous engorgement caused in the nasal mucosa by the smooth muscle relaxant effect of PDE-5 inhibitors is combined with a second event (e.g., specific drugs or blood dyscrasia). Emergency physicians should be also aware of the possibility that in the coming years the number of such cases might increase because of the increased use of these medications for erectile dysfunction or recreational purposes. It is likely that these patients could not be managed conservatively, but would rather require referral to an Ear, Nose, and Throat Department for surgical intervention., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Schizophrenia symptoms are associated with alterations in basal ganglia-cortical networks that include the cyclic nucleotides (cAMP/cGMP) signaling pathways. Phosphodiesterase 10A (PDE10A) inhibitors have been considered as therapeutic agents for schizophrenia because the regulation of cAMP and cGMP in the striatum by PDE10A plays an important role in the signaling mechanisms of the striatal-cortical network, and thereby in cognitive function. In the present study we assessed in non-human primates (NHPs) the effects of a novel PDE10A inhibitor (FRM-6308) that has demonstrated high potency and selectivity for human recombinant PDE10A in vitro. The behavioral effects of FRM-6308 in a dose range were determined in rhesus monkeys using a standardized motor disability scale for primates, motor tasks, and the "drug effects on the nervous system" (DENS) scale. The neuronal metabolic effects of FRM-6308 were determined with [(18)F]-fluorodeoxyglucose PET imaging. Results showed that FRM-6308 did not have any specific effects on the motor system at s.c. doses up to 0.32 mg/kg in NHPs, which induced a significant increase in the FDG-SUV in striatum (F 16.069, p < 0.05) and cortical (F 15.181, p < 0.05) regions. Higher doses induced sedation and occasional involuntary movements with clear development of tolerance after repeated exposures. These findings suggest that FRM-6308 has the adequate pharmacological profile to advance testing in clinical trials and demonstrate antipsychotic efficacy of PDE10A inhibition for the treatment of schizophrenia patients., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Aim: The aim of this review was to summarize the ocular action of the most common phosphodiesterase (PDE) inhibitors used for the treatment of erectile dysfunction and the subsequent visual disorders., Method: This is a literature review of several important articles focusing on the pathophysiology of visual disorders induced by PDE inhibitors., Results: PDE inhibitors have been associated with ocular side effects, including changes in color vision and light perception, blurred vision, transient alterations in electroretinogram (ERG), conjunctival hyperemia, ocular pain, and photophobia. Sildenafil and tadalafil may induce reversible increase in intraocular pressure and be involved in the development of non-arteritic ischemic optic neuropathy. Reversible idiopathic serous macular detachment, central serous chorioretinopathy, and ERG disturbances have been related to the significant impact of sildenafil and tadalafil on retinal perfusion., Discussion: So far, PDE inhibitors do not seem to cause permanent toxic effects on chorioretinal tissue and photoreceptors. However, physicians should write down any visual symptom observed during PDE treatment and refer the patients to ophthalmologists., Competing Interests: The authors report no conflicts of interest in this work.

Rationale: Schizophrenia is a complex neuropsychiatric disorder characterized, in part, by impaired dopamine signaling. TAK-063 is a selective inhibitor of phosphodiesterase 10A, a key regulator of intracellular signaling pathways that is highly expressed in the striatum., Objective: Safety, tolerability, and pharmacokinetics of TAK-063 were evaluated in a phase 1 study., Methods: Healthy Japanese and non-Japanese volunteers were randomized into dose cohorts of 3, 10, 30, 100, 300, and 1000 mg. Each fasting volunteer randomly received a single dose of TAK-063 or placebo. Individuals from the 100-mg cohort also received a post-washout, 100-mg dose under fed conditions. A total of 84 volunteers enrolled (14 per cohort)., Results: The most common drug-related adverse events (AEs) were somnolence (33.3 %), orthostatic tachycardia (19.7 %), and orthostatic hypotension (9.1 %). The three severe AEs recorded occurred at the highest doses: orthostatic hypotension (n = 1; 300 mg) and somnolence (n = 2; 1000 mg). There were no deaths, serious AEs, or discontinuations due to AEs. TAK-063 exposure increased in a dose-dependent manner. Median T max was reached 3 to 4 h postdose. Fed conditions slowed absorption (T max =  6 h) and increased oral bioavailability. Renal elimination was negligible. Safety and pharmacokinetic parameters were similar between Japanese and non-Japanese subjects. Impairments in cognitive function consistent with the effects of other sedative or hypnotic agents were detected using a validated, computerized cognition battery, CNS Vital Signs., Conclusions: TAK-063 was safe and well tolerated at doses up to 1000 mg and demonstrated a pharmacokinetic profile supporting once-daily dosing. Further evaluation of the clinical safety and efficacy of TAK-063 is warranted., Competing Interests: Compliance with ethical standards Role of funding source Funding for this study was provided by Takeda Pharmaceutical Company, Limited. Conflicts of interest Max Tsai, Thomas Macek, Lambros Chrones, and Jinhui Xie are employees of Takeda Development Center Americas, Inc., Deerfield, IL. Hakop Gevorkyan is an employee of California Clinical Trials Medical Group, Glendale, CA, and was Principal Investigator of the study.