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There is an urgent need to identify safe and effective combination treatments for multidrug-resistant (MDR) Mycobacterium tuberculosis infection (TB). Bedaquiline, a new diarylquinoline, is approved for the treatment of MDR pulmonary TB in combination with other drugs, which could include rifabutin, which is also used to treat drug-resistant TB. Both rifabutin and bedaquiline are metabolized via cytochrome P450 3A4, and rifabutin is an inducer of this enzyme. Bedaquiline is metabolized into its primary N-monodesmethyl metabolite, M2, and further desmethylated into an N-didesmethyl metabolite, M3. Both metabolites are cytotoxic and induce phospholipidosis. The effect of rifabutin on the generation and disposition of the 2 metabolites was investigated in healthy adult volunteers coadministered bedaquiline and either rifabutin or rifampin. Subjects received single oral doses (400 mg) of bedaquiline on days 1 and 29. Oral rifabutin (300 mg) or rifampin (600 mg) were given daily on days 20-41. In the rifabutin group maximum M2 concentrations (Cmax ) increased significantly (P < .001) from 47.59 to 79.53 ng/mL, and clearance slowed slightly (P = .01). This resulted in significantly (P < .001) increased overall exposure (area under the concentration-time curve [AUC0-τ ]). Peak concentrations of M3 increased approximately 3-fold with little decline thereafter. In rifampin recipients M2 Cmax doubled (48.44 to 101.52 ng/mL), but M2 clearance and time to Cmax significantly (P < .001) increased, and AUC0-∞ and mean residence time significantly decreased (P < .001). Peak M3 concentrations increased 4-fold and rapidly declined. Although both rifamycins accelerate desmethylation of bedaquiline and M2, differences in clearance resulted in sustained elevations of both metabolites during rifabutin, but not rifampin, treatment.

Background The broad-spectrum cephalosporin ceftaroline, a metabolite of the prodrug ceftaroline fosamil, has shown in vitro activity against clinical isolates from pediatric patients. Methods This multicenter, randomized, observer-blinded, active-controlled study (NCT01669980) assessed the safety and effectiveness of ceftaroline fosamil compared with ceftriaxone plus vancomycin in patients between 2 months and 17 years of age with complicated community-acquired bacterial pneumonia. Patients were randomized 3:1 (stratified by age cohort) to receive either ceftaroline fosamil or ceftriaxone plus vancomycin (comparator) as intravenous therapy for ≥3 days. Patients who met specific study criteria on or after Study Day 4 were permitted to switch to an oral study drug. Safety assessments were treatment-emergent adverse events, and the effectiveness of treatment was assessed by clinical and microbiologic outcomes. Results The median duration of intravenous treatment was 9.0 (range, 3.0-19.0) days in the ceftaroline fosamil group (N=30) and 7.5 (5.0-13.0) days in the comparator group (N=10). At least one treatment-emergent adverse event was experienced by 12/30 patients (40%) in the ceftaroline fosamil group and 8/10 (80%) in the comparator group; most treatment-emergent adverse events in both groups were mild to moderate in intensity. Clinical response rates in the modified intent-to-treat population were 52% (15/29 patients) in the ceftaroline fosamil group and 67% in the comparator group (6/9); clinical stability at Study Day 4 was 21% (6/29) and 22% (2/9), respectively. Conclusions Ceftaroline fosamil was well tolerated and showed similar clinical response rates to ceftriaxone plus vancomycin in pediatric patients with complicated community-acquired bacterial pneumonia.

The Best Pharmaceuticals for Children Act of 2002 mandated that the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) carries out critical reviews of the gaps in knowledge and unmet needs regarding safe and effective pharmacologic treatment of infants, children, and adolescents in a broad range of disease areas. In 2012, NICHD selected diabetes mellitus as one of the pediatric disorders for review. Dr. William V. Tamborlane was named chair, and Dr. Linda DiMeglio, vice-chair, of the Diabetes Working Group. Together with Dr. George Giacoia of NICHD, they assembled a distinguished group of medical experts in childhood diabetes, including clinicians/clinical investigators from leading academic centers and from industry and representatives from the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA), and the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), to carry out this review. It is very important to note that the views expressed in this article, as well as in other reports from the Diabetes Working Group, are the personal views of the authors and may not be understood or quoted as being made on behalf of or reflecting the position of the FDA or EMA or any of the organizations or pharmaceutical companies represented in our working group. As shown in Supplementary Table 1, the large Diabetes Working Group was divided into five committees: Type 1 Diabetes (T1D): Therapeutics, Type 2 Diabetes (T2D): Therapeutics, T1D: Natural History and Biomarkers, T2D: Natural History and Biomarkers, and Diabetes Pharmacology. The consensus of the T2D Therapeutics Committee was that its efforts should address the crisis in care that clinicians face in treating this disorder in adolescents. Despite a plethora of new drug classes and new agents within each class that have been approved for use in adults with T2D, in …

This article describes the simultaneous determination of bedaquiline fumarate (TMC-207) and rifabutin in human plasma by stable isotope dilution tandem mass spectrometry. The methodology was developed for an investigation of potential drug-drug interactions of the two anti-tuberculosis drugs when given together to healthy human volunteers. Use of the two drugs in combination to treat disease caused by Mycobacterium tuberculosis is contemplated as the bacterium becomes resistant to many currently available drugs.

Author(s): Barbee, Lindley A; Nayak, Seema U; Blumer, Jeffrey L; OʼRiordan, Mary Ann; Gray, Wesley; Zenilman, Jonathan M; Golden, Matthew R; Griffiss, J McLeod | Abstract: BACKGROUND:There are no fully oral recommended treatment regimens for gonorrhea. Inadequately treated pharyngeal gonococcal infections are a likely reservoir for transmission and development of antimicrobial resistance. We sought to determine an oral cefixime dosing regimen that would theoretically treat pharyngeal infections by gonococci with minimum inhibitory concentrations 0.5 μg/mL. METHODS:We conducted an open-label, nonrandomized, phase I pharmacokinetic and safety study of cefixime in 25 healthy male and female volunteers divided into 4 dosing cohorts (cohort A, 400 mg; cohort B, 800 mg; cohort C, 1200 mg; and cohort D, 800 mg every 8 hours × 3 doses [total dose 2400 mg]) with a target serum concentration of at least 2.0 μg/mL for more than 20 hours. Cefixime concentrations from serum and pharyngeal fluid were determined with use of a validated liquid chromatography-tandem mass spectrometry assay. Safety measures included laboratories, physical examinations, and symptom diaries. RESULTS:None of the single-dose regimens attained the target concentration; however, 50% of subjects in cohort D attained the target concentration. Variation in absorption and protein binding contributed to differences in concentrations. Pharyngeal fluid concentrations were negligible. The single-dose regimens were well tolerated; the multidose regimen resulted in mild to moderate gastrointestinal symptoms in 43% of subjects. CONCLUSIONS:None of the dosing regimens achieved the target concentration. However, the proposed theoretical target was extrapolated from penicillin data; there are no empirically derived pharmacokinetic/pharmacodynamic criteria for pharyngeal gonorrhea. Under alternative cephalosporin-specific therapeutic goals, the multidose regimen may be effective, although the absence of cefixime in pharyngeal fluid is concerning. A clinical trial evaluating efficacy and defining pharmacokinetic/pharmacodynamic outcomes may be warranted.

Bedaquiline is a diarylquinoline that specifically inhibits mycobacterial ATP synthase. Bedaquiline has been used to effectively treat tuberculosis (TB) caused by drug-susceptible and drug-resistant Mycobacterium tuberculosis . Rifamycins are a cornerstone of combination drug regimens for the treatment of TB. This phase 1, open-label, randomized, controlled trial evaluated the effect of steady-state dosing of rifabutin or rifampin on the safety, tolerability, and pharmacokinetics of bedaquiline given as a single dose. Thirty-three healthy subjects were enrolled to receive a 400-mg single oral dose of bedaquiline at two time points, on study days 1 and 29. Subjects were randomly assigned to once daily oral doses of rifabutin (300 mg/day, n = 17) or rifampin (600 mg/day, n = 16) during period 2 from days 20 to 41. Serial blood sampling for bedaquiline measurement occurred on days 1 and 29 through 336 h after bedaquiline administration. The day 29 bedaquiline pharmacokinetic parameter estimates were compared to the corresponding day 1 estimates for each rifamycin group. Steady-state rifampin reduced bedaquiline AUC 0–336 approximately 45%, from 47.69 h·μg/ml in period 1 to 26.33 h·μg/ml in period 2. Bedaquiline apparent clearance accelerated 24% in rifampin-treated subjects from 6.59 liters/h in period 1 to 8.19 liters/h in period 2. Steady-state rifabutin resulted in little quantitative impact on bedaquiline exposure but was associated with grade 3 and 4 adverse events before and after the day 29 bedaquiline dose. Dosage adjustments may therefore be necessary to ensure that bedaquiline plasma concentrations reach therapeutic levels safely when combining bedaquiline and rifamycins in TB treatment regimens. (This single-site, randomized, open-label, prospective study in healthy adult volunteers was registered at Clinicaltrials.gov under registration no. NCT01341184.)

Background Bedaquiline, an antimycobacterial agent approved for drug-resistant tuberculosis, is metabolized by CYP3A4, an hepatic enzyme strongly induced by rifampin, an essential part of drug-sensitive tuberculosis treatment. We examined the pharmacokinetic interactions of bedaquiline plus either rifampin or rifabutin in 33 healthy volunteers. This sub-study of that trial examined the mycobactericidal activity of these drugs against intracellular Mycobacterium tuberculosis using ex vivo whole blood culture. Methods Subjects were randomly assigned to receive two single 400 mg doses of bedaquiline, alone, and, after a 4 week washout period, in combination with steady-state daily dosing of either rifabutin 300 mg or rifampin 600 mg. Blood samples were collected prior to dosing and at multiple time points subsequently, to measure plasma drug concentrations and bactericidal activity in ex vivo M tuberculosis-infected whole blood cultures (WBA). Results Single oral doses of bedaquiline produced readily detectable WBA ex vivo, reaching a maximal effect of -0.28 log/day, with negative values indicating bacterial killing. Plasma concentrations of 355 ng/ml were sufficient for intracellular mycobacteriostasis. Combined dosing with rifampin or rifabutin produced maximal effects of -0.91 and -0.79 log/d, respectively. However, the activity of the rifabutin combination was sustained throughout the dosing interval, thereby producing a greater cumulative or total effect. At low drug concentrations, rifabutin plus bedaquiline yielded greater mycobactericidal activity than the sum of their separate effects. Neither drug metabolites nor cellular drug accumulation could account for this observation. Conclusions The combination of rifabutin plus bedaquiline produces sustained intracellular mycobactericidal activity that is greater than the sum of their individual effects. Further studies of the treatment-shortening potential of this combination are warranted.

Despite over 40 years of worldwide usage, relatively few data have been published on the pharmacokinetics of cefazolin in pediatric surgical patients. The primary objectives of this study were to examine the pharmacokinetics and safety of cefazolin in children 10 to 12 years of age (inclusive) receiving 1 or 2 g of cefazolin, based on body weight. This multiple-center, open-label study enrolled pediatric patients electively scheduled for surgical procedures who required cefazolin as part of their routine clinical management. Patients weighing ≥25 to

BACKGROUND: Children with severe influenza infection may require parenteral therapy if oral or inhaled therapies are ineffective or cannot be administered. Results from a study investigating intravenous (IV) zanamivir for the treatment of hospitalized infants and children with influenza are presented. METHODS: This phase II, open-label, multicenter, single-arm study assessed the safety of investigational IV zanamivir in hospitalized children with influenza. Safety outcomes included treatment-emergent adverse events (TEAEs), clinical laboratory measurements, and vital signs. Clinical outcomes, pharmacokinetics, and virologic efficacy data were collected as key secondary outcomes. RESULTS: In total, 71 children received treatment with investigational IV zanamivir (exposure comparable to 600 mg twice daily in adults). TEAEs and serious TEAEs (STEAEs) were reported in 51 (72%) and 15 (21%) patients, respectively. The mortality rate was 7%, and median durations of hospital and ICU stays were 6 and 7.5 days, respectively. No STEAEs or deaths were considered related to IV zanamivir treatment, and no patterns of TEAEs, laboratory abnormalities, or vital signs were observed. The mean zanamivir exposures from 34 patients with normal renal function who received 12 mg/kg, 14 mg/kg, or 600 mg of IV zanamivir ranged from 64.5 to 110 hour·µg/mL. The median change from baseline in the viral load was −1.81 log10 copies per mL after 2 days of treatment. CONCLUSIONS: The safety profile of IV zanamivir was favorable, with no drug-related STEAEs reported. The majority of children experienced virologic response and clinical improvement during the treatment course. Systemic zanamivir exposures in children were consistent with adults.

Clostridium difficile causes antibiotic-associated diarrhea and is a major public health concern. Current therapies disrupt the protective intestinal flora, do not reliably prevent recurrent infections, and will be decreasingly effective should less susceptible strains emerge. CRS3123 is an oral agent that inhibits bacterial methionyl-tRNA synthetase and has potent activity against C. difficile and aerobic Gram-positive bacteria but little activity against Gram-negative bacteria, including anaerobes. This first-in-human, double-blind, placebo-controlled, dose escalation study evaluated the safety and systemic exposure of CRS3123 after a single oral dose in healthy adults. Five cohorts of eight subjects each received CRS3123 or placebo in a 3:1 ratio. Doses for the respective active arms were 100 mg, 200 mg, 400 mg, 800 mg, and 1,200 mg. Blood and urine were collected for pharmacokinetic analysis. CRS3123 concentrations were measured with validated LC-MS/MS techniques. There were no serious adverse events or immediate allergic reactions during administration of CRS3123. In the CRS3123-treated groups, the most frequent adverse events were decreased hemoglobin, headache, and abnormal urine analysis; all adverse events in the active-treatment groups were mild to moderate, and their frequency did not increase with dose. Although CRS3123 systemic exposure increased at higher doses, the increase was less than dose proportional. The absorbed drug was glucuronidated at reactive amino groups on the molecule, which precluded accurate pharmacokinetic analysis of the parent drug. Overall, CRS3123 was well tolerated over this wide range of doses. This safety profile supports further investigation of CRS3123 as a treatment for C. difficile infections. (This study has been registered at ClinicalTrials.gov under identifier NCT01551004.)

Serum penicillin G falls to low levels 2 weeks after injection as benzathine penicillin G (BPG) in young adults. Using Pmetrics and previously reported penicillin G pharmacokinetic data after 1.2 million units were given as BPG to 329 male military recruits, here we develop the first reported population pharmacokinetic model of penicillin G after BPG injection. We simulated time-concentration profiles over a broad range of pediatric and adult weights after alternative doses and dose frequencies to predict the probability of maintaining serum penicillin G concentrations of >0.02 mg/liter, a proposed protective threshold against group A Streptococcus pyogenes (GAS). The final population model included linear absorption into a central compartment, distribution to and from a peripheral compartment, and linear elimination from the central compartment, with allometrically scaled volumes and rate constants. With 1.2 million units of BPG given intramuscularly every 4 weeks in four total doses, only 23.2% of 5,000 simulated patients maintained serum penicillin G trough concentrations of >0.02 mg/liter 4 weeks after the last dose. When the doses were 1.8 million units and 2.4 million units, the percentages were 30.2% and 40.7%, respectively. With repeated dosing of 1.2 million units every 3 weeks and every 2 weeks for 4 doses, the percentages of simulated patients with a penicillin G trough concentration of >0.02 mg/liter were 37.8% and 65.2%, respectively. Our simulations support recommendations for more frequent rather than higher BPG doses to prevent recurrent rheumatic heart disease in areas of high GAS prevalence or during outbreaks.

Background: The prevalence and importance of hypertension in younger patients is becoming increasingly recognized; however, only a limited number of clinical trials have been conducted in the pediatric population. Objective: The aim of this study was to characterize the pharmacokinetics and short-term safety of olmesartan medoxomil in children and adolescents with hypertension. Methods: An open-label, multicenter, single-dose study was conducted in children and adolescents aged 12 months–16 years who were receiving treatment for hypertension or, if not currently treated for hypertension, had either a systolic blood pressure (SBP) or diastolic blood pressure (DBP) ≤95th percentile, or SBP or DBP ≤90th percentile if diabetic or with a family history of hypertension. Patients were stratified by age: 12–23 months (Group 1; none enrolled), 2–5 years (Group 2; n = 4), 6–12 years (Group 3; n = 10), and 13–16 years (Group 4; n = 10). All patients received a single oral dose of olmesartan medoxomil based on the individual’s age and bodyweight. Patients aged

Dalbavancin is a novel lipoglycopeptide antibiotic that has potent in vitro activity against Gram-positive microorganisms.We performed a phase 1, open-label, multicenter study to investigate the pharmacokinetics (PK) and safety of a single dose of intravenous dalbavancin in hospitalized pediatric subjects 3 months to 11 years of age. We combined these data with previously collected adolescent PK data and performed a population PK analysis.Model development was performed using 311 dalbavancin plasma concentrations from 43 subjects. The median age was 5.9 years (range: 0.3-16.9). A 3-compartment, linear PK model was developed. Based on simulations, the following age-dependent dosing regimen was found to achieve similar dalbavancin exposure to that in adults administered a 2-dose regimen: children 6 to18 years of age, 12 mg/kg (1000 mg maximum) on day 1 and 6 mg/kg (500 mg maximum) on day 8 and children 3 months to6 years of age, 15 mg/kg (1000 mg maximum) on day 1 and 7.5 mg/kg (500 mg maximum) on day 8. Similarly, the following age-dependent regimen was found to match adult exposure after a single-dose (1500 mg): 6 to18 years of age, 18 mg/kg (1500 mg maximum) on day 1 and 3 months to6 years of age, 22.5 mg/kg (1500 mg maximum) on day 1. Nineteen subjects experienced 36 treatment-emergent adverse events. Five of 36 adverse events were assessed as possibly or probably related to treatment.Dalbavancin pediatric dosing that matched adult exposure was identified. Overall, dalbavancin was well tolerated in our study population.

(See the Editorial Commentary by Jacqz-Aigrain, on pages 1503–4.) Intra-abdominal infections in young infants (

Ambulatory blood pressure monitoring (ABPM) has been proposed as a useful tool for more accurately diagnosing hypertension (HTN) and evaluating blood pressure (BP) response in pediatric anti-hypertensive trials. ABPM captures multiple BP measurements during routine daily activities and is thus an excellent method for identifying white-coat HTN. Additionally, ABPM measurements in adults do not demonstrate the placebo effect commonly seen with casual BP measurements, although this has yet to be evaluated in children. Therefore,, the aim of this study was to assess the effect of placebo on ABPM measurements in children. A total of 141 children aged 5–16 years with elevated BP were randomized into a multi-center, single-blind, cross-over trial. Subjects received a placebo pill prior to wearing a 24-h ABPM device at one of two visits separated by 1–2 weeks. Study procedures were otherwise identical at both visits. Mean systolic and diastolic BP for all measured time periods were similar between visits, as was the number of children diagnosed with HTN at each visit. Having confirmed HTN at baseline did not affect the impact of placebo on mean BP. If confirmed, this lack of placebo effect on ABPM measurements may allow for the design of direct comparison pediatric anti-hypertensive trials without a placebo arm.

The effectiveness and safety of valsartan have not been assessed in hypertensive children. Therefore, hypertensive patients aged 6 to 16 years (n=261) were randomized to receive weight-stratified low- (10/20 mg), medium- (40/80 mg), or high-dose (80/160 mg) valsartan for 2 weeks. After 2 weeks, patients were randomized to a 2-week placebo-controlled withdrawal phase. Dose-dependent reductions in sitting systolic blood pressure (SSBP) and sitting diastolic blood pressure (SDBP) were observed after 2 weeks (low dose, -7.9/-4.6 mm Hg; medium dose, -9.6/-5.8 mm Hg; high dose, -11.5/-7.4 mm Hg [P

A multicenter, open-label study evaluated the single-dose pharmacokinetics and safety of a pediatric oral famciclovir (prodrug of penciclovir) formulation in infants aged 1 to 12 months with suspicion or evidence of herpes simplex virus infection. Individualized single doses of famciclovir based on the infant's body weight ranged from 25 to 175 mg. Eighteen infants were enrolled (1 to n = 8], 3 to n = 5], and 6 to 12 months old [ n = 5]). Seventeen infants were included in the pharmacokinetic analysis; one infant experienced immediate emesis and was excluded. Mean C max and AUC 0-6 values of penciclovir in infants 0-6 was 2.2 μg·h/ml in infants aged 1 to

Gram-positive organisms are the most common cause of bacterial infections in infants, children, and adolescents, accounting for 80% of community-acquired and 60% of hospital-acquired bacterial infections. Antimicrobial treatment for infants and children is largely empirical in both the outpatient and hospital settings, despite emerging resistance patterns. Effective antimicrobial treatment from a pharmacological perspective relies on pharmacokinetic, pharmacodynamic, and pharmaceutical determinants. Pediatric patients present an additional challenge in selecting appropriate antimicrobial treatment for a specific pathogen because growth from infancy to sexual maturity results in profound changes in antibiotic disposition. Utilizing carefully generated pharmacokinetic, pharmacodynamic, and pharmaceutical data, tools exist to select the appropriate antimicrobial agent for treatment of Gram-positive infections in pediatric patients.

An open-label, single-dose study is conducted in 26 children with hypertension to characterize the pharmacokinetics of valsartan. Valsartan is administered as an oral suspension (dose of 2 mg/kg), with the maximum single dose being 80 mg. Subjects are stratified into 4 age categories: group 1, 1 to less than 4 years; group 2, 4 to less than 6 years; group 3, 6 to less than 12 years; group 4, 12 to 16 years. Blood samples are collected before and for 24 hours after dosing to quantitate valsartan. Because the body weight of most children in groups 3 and 4 exceeds 40 kg and they received a dose of less than 2 mg/kg, major pharmacokinetic parameters are dose normalized for comparison across the age groups. Dose-normalized maximum plasma concentration and area under the plasma-concentration curve and body weight-normalized apparent oral clearance are comparable for the 4 groups (P > or = .1011). Body weight-normalized apparent oral clearance ranges from 0.061 to 0.089 L/h/kg.

OBJECTIVE The carbapenems are broad-spectrum beta-lactam antibiotics with activity against most organisms encountered in the pediatric intensive care unit (PICU). In anticipation of their increased use in critically ill children, we measured the effect of sustained meropenem use on the pattern of Gram-negative bacillus colonization in patients admitted to a tertiary care PICU. DESIGN : Prospective preintervention/postintervention comparison. SETTING Medical/surgical PICU. PATIENTS Consecutive PICU admissions over 2.5 yrs. INTERVENTIONS After a 6-mo baseline period, all children with serious infections admitted to the PICU during the subsequent 2 yrs were administered meropenem. The incidence of colonization by Gram-negative bacilli resistant to one of a battery of broad-spectrum parenteral agents, and by organisms resistant specifically to meropenem, during the baseline period was compared with the period of preferred meropenem use. RESULTS During the period of preferred meropenem use, the amount of meropenem used increased >seven-fold, whereas the use of other advanced generation beta-lactams was reduced by nearly 80%. The mean prevalence of colonization by antibiotic-resistant bacilli in general was not statistically altered during the period of meropenem preference (7.3 organisms/100 patient-days, vs. 9.4 organisms/100 patient-days at baseline, p < 0.09). The prevalence of colonization by Gram-negative organisms resistant specifically to meropenem was 0.61 organisms/100 patient-days during the baseline period vs. 1.04 organisms/100 patient-days during the period of meropenem preference (p < 0.30). The incidence of nosocomial infections did not change, and the prevalence of nosocomial infections caused by meropenem-resistant organisms was always

Background: Levofloxacin has established efficacy and safety in the treatment of community-acquired pneumonia (CAP) in adults, and its use as an alternative therapy for children with CAP has been proposed. Objective: Assess the clinical efficacy and safety of levofloxacin compared with standard of care antibiotic therapy in the treatment of CAP in children aged 6 months to 16 years. Methods: In an open-label, multicenter, noninferiority trial, children with CAP were randomized 3:1 to receive levofloxacin or comparator antimicrobial therapy (0.5 to 5 years: amoxicillin/clavulanate or ceftriaxone; 5 years: clarithromycin or ceftriaxone with clarithromycin or erythromycin lactobinate) for 10 days. The primary outcome was cure rates at the test-of-cure visit (10‐17 days after completing treatment) as determined by symptoms, physical examination, and chest radiography. Results: Seven hundred and thirty-eight children were enrolled and 539 (405 levofloxacin-treated, 134 comparator-treated) were clinically evaluable at test-of-cure visit. Clinical cure rates were 94.3% (382 of 405) in levofloxacin-treated and 94.0% (126 of 134) in comparator-treated children. Cure rates were also similar for levofloxacin and comparator for each age group (5 years, 92.2% versus 90.8%; 5 years, 96.5% versus 97.1%; respectively) and for children categorized as being at higher risk for severe disease. Mycoplasma pneumoniae was the most frequently identified cause of pneumonia (230 children). Levofloxacin was as well tolerated as comparators, with similar type and incidence of adverse events. Conclusions: Levofloxacin was as well tolerated and effective as standard-of-care antibiotics for the treatment of CAP in infants and children.

Background:Fluoroquinolones, including levofloxacin, have not been recommended for use in children largely because studies in juvenile laboratory animals suggest there may be an increased risk of fluoroquinolone-associated cartilage lesions. A large prospective trial is needed to assess the risks as

This investigation was designed to evaluate the single-dose pharmacokinetics of itraconazole, hydroxyitraconazole, and hydroxypropyl-β-cyclodextrin (HP-β-CD) after intravenous administration to children at risk for fungal infection. Thirty-three children aged 7 months to 17 years received a single dose of itraconazole (2.5 mg/kg in 0.1-g/kg HP-β-CD) administered over 1 h by intravenous infusion. Plasma samples for the determination of the analytes of interest were drawn over 120 h and analyzed by high-pressure liquid chromatography, and the pharmacokinetics were determined by traditional noncompartmental analysis. Consistent with the role of CYP3A4 in the biotransformation of itraconazole, a substantial degree of variability was observed in the pharmacokinetics of this drug after IV administration. The maximum plasma concentrations ( C max ) for itraconazole, hydroxyitraconazole, and HP-β-CD averaged 1,015 ± 692 ng/ml, 293 ± 133 ng/ml, and 329 ± 200 μg/ml, respectively. The total body exposures (area under the concentration-time curve from 0 to 24 h) for itraconazole, hydroxyitraconazole, and HP-β-CD averaged 4,922 ± 6,784 ng·h/ml, 3,811 ± 2,794 ng·h/ml, and 641.5 ± 265.0 μg·h/ml, respectively, with no significant age dependence observed among the children evaluated. Similarly, there was no relationship between age and total body clearance (702.8 ± 499.4 ml/h/kg); however, weak associations between age and the itraconazole distribution volume ( r 2 = 0.18, P = 0.02), C max (r 2 = 0.14, P = 0.045), and terminal elimination rate ( r 2 = 0.26, P < 0.01) were noted. Itraconazole infusion appeared to be well tolerated in this population with a single adverse event (stinging at the site of infusion) deemed to be related to study drug administration. Based on the findings of this investigation, it appears that intravenous itraconazole can be administered to infants beyond 6 months, children, and adolescents using a weight-normalized approach to dosing.

The pharmacokinetic (PK) parameters of lisinopril were obtained in 46 children aged 6 months to 15 years. A lisinopril suspension (0.15 mg/kg per day) was administered to patients6 years of age; the remaining children received lisinopril tablets, the daily dose being adjusted according to body weight, i.e., 2.5 mg if25 kg, 5 mg if 25-45 kg, and 10 mg if45 kg. Blood was drawn predose and on eight occasions postdose in children aged 4-15 years, and on five occasions in those aged4 years. PK data are reported for the 46 children in terms of age groups: Group I (n=9), aged 6-23 months; Group II (n=8), aged 2-5 years; Group III (n=12), aged 6-11 years; Group IV (n=17), aged 12-15 years. The dose of lisinopril ranged from 3.07 mg/m(2) per day in Group I to 4.78 mg/m(2) per day in Group IV. C(max) of lisinopril, which occurred 5-6 h postdose, varied from 22 ng/ml in Groups I and II to 44 ng/ml in Groups III and IV; AUC(0-24 h) ranged from 301-311 ng.h/ml in Groups I and II to 550-570 ng.h/ml in Groups III and IV. No serious adverse events related to lisinopril were reported.

The broad spectrum of antimicrobial activity, oral bioavailability, extensive tissue distribution, and once-daily intravenous or oral dosing of gatifloxacin, an expanded-spectrum 8-methoxy fluoroquinolone, make it a potentially useful agent for the treatment of pediatric infections. A population pharmacokinetic model was developed to describe the pharmacokinetics of gatifloxacin in children. Data for analysis were obtained from a single-dose safety/pharmacokinetic study utilizing intensive blood sampling in patients aged 6 months to 16 years. Each subject received a single oral dose of gatifloxacin as a suspension, at doses of 5, 10, or 15 mg/kg of body weight. A total of 845 samples were obtained from 82 patients. A one-compartment model with first-order absorption and elimination was the most appropriate to describe the gatifloxacin concentrations. Covariate analysis using forward selection and backward elimination found that apparent clearance was related to body surface area, and apparent volume of distribution was related to body weight. No effect of age on drug clearance could be identified once clearance was corrected for body surface area. Based on pharmacokinetic simulations, the 10-mg/kg (maximum, 400 mg) once-daily dose of gatifloxacin is expected to provide drug exposure similar to that in healthy adults. The population pharmacokinetic model described herein will be used for Bayesian analyses of sparse pharmacokinetic sampling in phase II/III clinical trials and for Monte Carlo simulation experiments. The success of this strategy provides a model for future pediatric drug development programs.

Background Cancer patients undergoing chemotherapy often develop anemia, which can increase the risk for transfusions and fatigue. The recombinant erythropoiesis-stimulating agent darbepoetin alfa can effectively treat chemotherapy-induced anemia (CIA) in adults, but limited data are available regarding its use in pediatric cancer patients. The goals of this phase 1, open-label, uncontrolled study were to assess the pharmacokinetic profile and safety of darbepoetin alfa in pediatric patients with CIA. Procedure Pediatric patients with nonmyeloid malignancies and CIA received up to six doses of darbepoetin alfa 2.25 mcg/kg subcutaneously. After the first dose, the pharmacokinetic properties of darbepoetin alfa were assessed during a 14-day sampling period. All subsequent doses were given weekly with predose blood samples collected before study drug administration. Results After a single dose of darbepoetin alfa, the mean (SD) peak serum concentration was 10.5 (3) ng/ml, and the median time to peak concentration was 71.4 hr. Darbepoetin alfa exhibited a mean (SD) terminal half-life of 49.4 (32) hr. Upon repeated weekly administration, no evidence of darbepoetin alfa accumulation was observed though there was high intra- and inter-individual variability. In addition, darbepoetin alfa was well tolerated; some study patients experienced increases in hemoglobin. Conclusions The pharmacokinetic profile of darbepoetin alfa indicated that it was slowly absorbed and exhibited a long terminal half-life in these pediatric study patients with CIA. Pediatr Blood Cancer 2007;49:687–693. © 2006 Wiley-Liss, Inc.

Objective: The use of short-term intramuscular ceftriaxone for pediatric ambulatory conditions raises concerns regarding the promotion of resistance among colonizing enteric bacteria. This study was designed to assess the prevalence of stool colonization with resistant Gram-negative bacilli after single-dose ceftriaxone treatment compared with other regimens for acute otitis media. Methods: Children age 3 months to 7 years and diagnosed with acute otitis media were randomized to receive treatment with single-dose ceftriaxone or with oral cefprozil, amoxicillin or azithromycin. Stool samples were obtained at enrollment and then 3-5 days, 10-14 days, and 28-30 days after therapy was initiated and screened for the presence of facultative Gram-negative bacilli resistant to ceftriaxone, cefprozil, amoxicillin, piperacillin, piperacillin-tazobactam and tobramycin. Mean prevalence of colonization by resistant organisms for each treatment group was compared at each time point. Results: One thousand nine subjects were enrolled. The prevalence of colonization by a Gram-negative bacillus resistant to at least 1 of the screening antibiotics decreased after receipt of ceftriaxone but returned close to values measured at study entry by 30 days. A qualitatively similar pattern was noted for the 3 other regimens, but a quantitatively greater decrease in the prevalence of colonization by a resistant bacterium was noted at the 3- to 5-day and 10- to 14-day visits among azithromycin recipients (P < 0.001). Colonization by a Gram-negative bacillus resistant specifically to ceftriaxone was unusual at each study visit, regardless of treatment assignment. Conclusions: A single intramuscular dose of ceftriaxone had a similar effect on the prevalence of antibiotic-resistant Gram-negative facultative bacilli in the stool of healthy children when compared with commonly used oral agents.

Background Ambulatory blood pressure monitoring techniques provide unique advantages for diagnosing hypertension, although few devices have been independently validated in the pediatric population. Methods We sought to validate the accuracy of ambulatory blood pressure monitoring with the Spacelabs 90217 monitor in children using a modified British Hypertension Society protocol. Results A total of 112 children, aged between 6 and 17 years, completed the study at one of the three participating centers. Overall, the monitor earned an 'A' for systolic blood pressure and 'B' for diastolic blood pressure. It performed slightly better among 6-12 year olds (A/A) compared with 13-17 year olds (A/B). Conclusions We conclude that the Spacelabs 90217 monitor is an appropriate monitor for use in children who are 6 years of age or older.

Candidal fungal infection rates in neonates are increasing and are a significant cause of mortality, especially in low birth weight infants. Micafungin is an echinocandin that works by inhibiting 1,3-beta-D-glucan synthase, an enzyme responsible for fungal cell wall synthesis. The objective of this study was to determine the safety and pharmacokinetics of micafungin in premature infants.: This was a phase I, single-dose, multicenter, open-label, sequential-dose trial of intravenous micafungin investigating 3 doses (0.75 mg/kg, 1.5 mg/kg and 3.0 mg/kg) in 18 premature infants weighing1000 g (n = 6 in each dosage group). A further 5 infants (500-1000 g) were enrolled in the 0.75 mg/kg dosage group only.: The mean +/- standard deviation gestational age in the1000 g dosage group was 26.4 +/- 2.4 weeks and, on entry, patients had one or more of a variety of underlying conditions, including sepsis, pneumonia and other infections caused by Candida or other species. Micafungin pharmacokinetics in preterm infants appears linear. However, premature infants1000 g on average displayed a shorter half-life (8 hours) and a more rapid rate of clearance (approximately 39 mL/h per kg) compared with published data in older children and adults. All doses of micafungin were well tolerated and no serious drug-related adverse events were observed.: Single doses of micafungin, ranging up to 3.0 mg/kg, appear well tolerated in premature infants weighing1000 g. The drug's elimination half-life and total plasma clearance in preterm infants appear dissimilar to published values for these parameters in older children and adults. The reason(s) for this apparent difference remain to be investigated.

Cystic fibrosis (CF) is characterized by chronic pulmonary infection with acute pulmonary exacerbations (APEs) requiring IV antibiotic treatment. We report on a blinded comparative trial of IV meropenem (40 mg/kg to 2 g q8h) or ceftazidime (5 mg/kg to 2 g q8h), each of which was administered with IV tobramycin (at a serum peak ofor = 8 microg/mL and a trough of2 microg/mL), as treatment for CF patients with APEs.Patients who wereor = 5 years of age who were infected with ceftazidime-susceptible Pseudomonas aeruginosa were stratified by lung function and randomized to treatment with meropenem/tobramycin or ceftazidime/tobramycin. Patients infected with Burkholderia cepacia complex or ceftazidime-resistant P aeruginosa were assigned to receive open-label meropenem/tobramycin. Clinical response was assessed by spirometry to determine the change in percent predicted FEV1 and by a clinical acute change score (ACS).One hundred two patients were randomized to meropenem/tobramycin (n = 50) or ceftazidime/tobramycin (n = 52). Nineteen patients received open-label meropenem/tobramycin. FEV1 was improved at the end of treatment (EOT) with meropenem/tobramycin (mean [+/- SD] increase, 38.8 +/- 52.3%) and with ceftazidime/tobramycin (mean increase, 29.4 +/- 35.1%; p0.0001 vs baseline values). The proportion of patients withor = 15% relative increase from baseline FEV1 (satisfactory response) at day 7 was 62% for the meropenem/tobramycin group and 44% for the ceftazidime/tobramycin group (p = 0.04). The median time to FEV1 response was 4 days for meropenem/tobramycin therapy vs 6 days for ceftazidime/tobramycin therapy. Similarly, FEV1 improved in the open-label group (mean increase, 12.5 +/- 25.7%; p = 0.05). ACS improved in all three groups at EOT (p0.0001 vs baseline values).Therapy with both meropenem/tobramycin and ceftazidime/tobramycin improved pulmonary and clinical status and reduced sputum bacterial burden in CF patients with APEs. A larger proportion of patients receiving meropenem/tobramycin therapy demonstrated a satisfactory FEV1 response at day 7. Resistant P aeruginosa emerged infrequently during treatment with both regimens.

Objective. To explore pharmacokinetic factors underlying the poor bacteriologic eradication rate with a single 500-mg dose of ceftriaxone for streptococcal tonsillopharyngitis and to identify the minimum ceftriaxone dose required for effective treatment. Methods. Population modeling techniques were applied to pharmacokinetic data derived from paired plasma and tonsil samples from 153 children to assess the contribution of pharmacokinetic variability to patients' responses to ceftriaxone. In addition, a Monte Carlo simulation was performed to determine (1) the amount of time that free ceftriaxone concentrations must exceed the minimum inhibitory concentration (MIC) of group A Streptococcus to achieve bacteriologic eradication and (2) the ceftriaxone dose required to maintain free drug concentrations above the target MIC for the requisite amount of time. Ceftriaxone MICs for group A Streptococcus were obtained from a previous trial, in which all MICs (n = 115) were ≤0.064 mg/L; 33.9% were susceptible at ≤0.016 mg/L, 66.4% were susceptible at 0.032 mg/L, and 1.7% were susceptible at 0.064 mg/L. Results. Mean population pharmacokinetic parameters and their variances reflected substantial variability of clearance and half-life in the target population. Tonsillar ceftriaxone protein binding was 89.1%. The proportions of 1000 simulated patients with free ceftriaxone concentrations that exceeded MICs of 0.016 mg/L, 0.032 mg/L, and 0.064 mg/L at 24 hours were 71.7%, 65.4%, and 57.2%, respectively, and at 48 hours were 41.8%, 35.8%, and 28.6%, respectively. The amount of time that free ceftriaxone concentrations need to exceed MIC to achieve bacteriologic success was estimated to be 36 hours. Using this time criterion, two 500-mg doses of ceftriaxone separated by 18 hours should achieve a bacteriologic cure rate of ∼95%. Conclusions. Pharmacokinetic variability and high ceftriaxone tonsillar protein binding explain the high microbiologic failure rate for a single 500-mg dose of ceftriaxone in group A streptococcal tonsillopharyngitis. Monte Carlo simulation suggests that a second dose administered 18 hours after the first will be required to achieve an acceptable bacteriologic cure rate.

Gatifloxacin is an 8-methoxy fluoroquinolone effective against a broad spectrum of pathogens common in pediatric infections. The safety and pharmacokinetics of a single dose of gatifloxacin were studied in pediatric patients from 6 months to 16 years of age. Seventy-six pediatric patients (average age, 6.7 ± 5.0 years) were administered a single oral dose of gatifloxacin suspension (5, 10, or 15 mg/kg of body weight; 600-mg maximum) in a dose-escalating manner. Subjects were stratified by age into 4 groups. An additional 12 children, greater than 6 years of age, received gatifloxacin as the tablet formulation at a dose of approximately 10 mg/kg. Gatifloxacin's apparent clearance and half-life were 5.5 ± 2.1 ml/min/kg and 5.1 ± 1.4 h. The maximum concentration of drug in plasma and area under the concentration-time curve (AUC) increased in a manner approximately proportional to the dose. At the 10-mg/kg dose, the bioavailability was similar between the suspension and tablet formulation. The apparent oral clearance of gatifloxacin, normalized for body weight, exhibited a small but statistically significant decrease with increasing age. In all subjects receiving gatifloxacin at 10 mg/kg, the AUC exceeded 20 μg · h/ml (estimated free AUC/MIC ratio of ≥34 for MIC of ≤0.5 μg/ml). These data suggest that gatifloxacin at a dose of 10 mg/kg every 24 h will achieve therapeutic concentrations in plasma in infants and children.

The aim of this study was to determine the dose-response relationship for losartan, 2.5 to 100 mg, and to assess the safety and tolerability of losartan in hypertensive children 6 to 16 years of age.This was a multicenter, randomized, double-blind, dose-response study. In Period 1, a total of 175 patients were stratified by weight (50 kg and/=50 kg) and randomized to one of three dose groups by stratum (low, 2.5/5.0 mg; middle, 25/50 mg; or high, 50/100 mg) for 3 weeks. The ratio of the three dose levels for both weight strata was 1:10:20. In Period 2, patients in each dose group were randomized to continue the same treatment or placebo washout for 2 additional weeks.In Period 1, sitting trough diastolic blood pressure (DBP) decreased in a dose-dependent manner (P.0001). At week 3, changes in DBP from baseline in the low-, middle-, and high-dose groups were -6.0 mm Hg, -11.7 mm Hg, and -12.2 mm Hg, respectively. In Period 2, DBP increased significantly in patients who switched from middle- and high-dose losartan to placebo (mean increase 6.0 mm Hg, P = .003) relative to DBP in patients who remained on active treatment; however, these levels remained stable in those patients who switched from low-dose losartan to placebo (mean increase 1.1 mm Hg, P = .628).In hypertensive children 6 to 16 years of age, losartan given once daily reduced blood pressure in a dose-dependent fashion. A once-daily starting dose of losartan, 0.75 mg/kg (maximum 50 mg) effectively lowered DBP within 3 weeks. Losartan up to a dosage of 1.44 mg/kg (maximum 100 mg) once daily is generally well tolerated.

Although famotidine pharmacokinetics are similar in adults and children older than 1 year of age, they differ in neonates owing to developmental immaturity in renal function. Little is currently known about the pharmacokinetics of famotidine in infants aged between 1 month and 1 year, a period when renal function is maturing.To characterise the pharmacokinetics of famotidine in infants.This was a two-part multicentre study with both single dose (Part I, open-label) and multiple dose (Part II, randomised) arms.Thirty-six infants (20 females and 16 males) who required treatment with famotidine and who had an indwelling arterial or venous catheter for reasons unrelated to the study.Infants in Part I were administered a single dose of famotidine 0.5 mg/kg; the dose was intravenous or oral according to the judgement of the attending physician. Infants receiving 0.5 mg/kg intravenously were divided into two groups by age, and pharmacokinetic parameters in infants 0-3 months and3 to 12 months of age were compared. Infants in Part II were randomised to one of the following treatments: 0.25 mg/kg/dose intravenously or 0.5 mg/kg/dose orally on day 1 and subsequent days, or 0.25 mg/kg/dose intravenously or 0.5 mg/kg/dose orally on day 1 followed by doses of either 0.5 mg/kg/dose intravenously or 1 mg/kg/dose orally on subsequent days. From day 2 onwards, age-adjusted dose administration regimens (once daily in infants3 months of age and every 12 hours in infants3 months of age) were used; the total number of famotidine doses ranged from 3 to 11 and the total number of days of dose administration ranged from two to eight.In infants3 months of age, plasma and renal clearance of famotidine were decreased compared with infants3 months of age. Pharmacokinetic parameters for the older infants (i.e. those3 months) were similar to those previously reported for children and adults. Approximate dose-proportionality, no accumulation on multiple dosing and an estimated bioavailability similar to adult values were also observed.A short course of famotidine therapy in infants appears generally well tolerated, and the characteristics of famotidine pharmacokinetics during the first year of life are explained to a great degree by the development of renal function, the primary route of elimination for this drug.

The aim of this study was to examine the effectiveness of quetiapine in adolescents suffering from autistic disorder (AD).This was a 12-week, open-label study, for which medically healthy patients with AD between the ages of 10 and 17 years were eligible. Quetiapine treatment was gradually increased over the first 6 weeks of the study, to a total daily dose of 300 mg/day. Doses could then be increased to a maximum daily dose of 750 mg/day. Outcome measures included the Children's Psychiatric Rating Scale (CPRS) and the Clinical Global Impressions (CGI) scale.Nine (9) males were enrolled. Six (6) patients had previously been treated with other psychotropic agents. Although improvements in several symptom domains were observed on quetiapine, only 2 patients met a priori criteria for response ("much" or "very much improved" on the Clinical Global Impressions-Improvement Scale). In addition, only these same 2 patients' parents/guardians chose to continue quetiapine pharmacotherapy after study participation.These data suggest that quetiapine may not be a particularly effective agent in the treatment of adolescent patients with AD. However, should future studies be performed, it seems reasonable that they be conducted with more rigor, less treatment-resistant cohorts, and, possibly, a different dosing strategy.

Objective This pilot study examined the effectiveness, safety, tolerability, and pharmacodynamics of Hypericum perforatum (St. John's wort) in the treatment of youths diagnosed with major depressive disorder. Method Youths 6 to 16 years of age meeting DSM-IV criteria for major depressive disorder with depressive symptoms of at least moderate severity were eligible to enroll between January 1999 and January 2001 in this 8-week, prospective, open-label, outpatient study. Outcome measures included the Children's Depression Rating Scale-Revised (CDRS-R) and the Clinical Global Impressions (CGI) scale. A priori criteria for response consisted of a CDRS-R score of ≤28 and a CGI severity score ≤2. Patients were initially prescribed 150 mg St. John's wort three times daily. If at the end of week 4 the patient did not meet a priori response criteria, the dose was increased to 300 mg three times daily. Results Thirty-three youths with a mean (SD) age of 10.5 (2.9) years were enrolled. After 4 weeks of St. John's wort therapy, 22 youths had their dose increased to 900 mg/day. Twenty-five of the patients met response criteria after 8 weeks of treatment. Overall, St. John's wort was well tolerated. Conclusion St. John's wort may be an effective treatment for youths diagnosed with major depressive disorder. Placebo controlled trials seem indicated.

Background. Cefepime has activity against many hospital-acquired Gram-negative pathogens resistant to earlier beta-lactam antibiotics. This study was designed to test whether preferential use of cefepime in a pediatric intensive care unit could reduce enteric colonization with antibiotic-resistant Gram-negative rods. Methods. After a 6-month period of uncontrolled antibiotic use, cefepime was preferentially used during 2 years as treatment for nosocomial or serious community-acquired infection. Rectal swab specimens were obtained daily on every patient regardless of antibiotic exposure during the 6 months of uncontrolled antibiotic use and during the first and last 6 months of the 2 years of cefepime preference. The study outcome was rectal colonization with a facultative Gram-negative rod resistant to at least one of four antibiotics: cefepime; ceftazidime; gentamicin; or piperacillin-tazobactam. Results. The incidence of colonization by a resistant organism decreased only slightly during the first 6 months of cefepime use. By contrast, the number of antibiotic-resistant bacilli isolated from rectal swab specimens diminished from 27.6/100 patients during the baseline period to 12.9/100 patients by the last 6 months of the 2 years of cefepime preference (P < 0.01). The proportion of patients harboring at least one resistant organism decreased from 11.6% to 7.4% during the same time period (P < 0.01). A decrease in colonization with resistant organisms occurred for all the tested resistance phenotypes, including cefepime. Conclusion. Cefepime may possess a low potential for promoting bacillary resistance in critically ill patients, suggesting that its preferential use might be a key element in limiting the presence of antibiotic resistance in the intensive care unit.

Background: In infants and children, treatment of Kawasaki disease (KD) with high-dose intravenous immunoglobulin (IVIG) and acetylsalicylic acid ([ASA] aspirin) diminishes inflammatory response and reduces the risk for coronary artery abnormalities. However, patients with high serum concentrations of tumor necrosis factor (TNF)-alpha, which is associated with vascular damage, may develop coronary artery lesions even with treatment. The hemorheologic agent pentoxifylline blocks the production of TNF-alpha and may be an appropriate adjunctive therapy to IVIG and ASA. Objective: The objective of this study was to assess the pharmacokinetic characteristics and tolerability of a new oral syrup formulation of pentoxifylline as an adjunct to IVIG and ASA in the treatment of KD in children. Methods: Hospitalized boys and girls aged 6 months to 5 years and who were diagnosed with KD within the first 10 days of illness were eligible. Patients were assigned to 1 of 4 pentoxifylline treatment groups, by dose level (dose levels 1, 2, 3, and 4: 10, 15, 20, and 25 mg/kg daily, respectively, divided into 3 doses). Six plasma samples collected at the time the first dose was administered, and 4 samples collected after administration of the last dose on study day 6, were assessed by high-performance liquid chromatography using noncompartmental and 1-compartment pharmacokinetic analyses for pentoxifylline and its active metabolite (M-1). TNF-alpha levels on days 1 and 6 were assessed using electroimmunoassay. Results: Fourteen boys and 10 girls were enrolled. The mean age, body weight, and illness day at study entry were 34.5 months, 13.8 kg, and 6, respectively. Pentoxifylline exhibited nonlinear kinetic characteristics, with median area under the plasma concentration–time curve from time 0 to infinity(AUC0–∞) values of 622, 3428, 8416, and 10,347 ng/mL · h for dose levels 1 to 4, respectively, on study day 1. Pentoxifylline noncompartmental oral clearance and volume of distribution were significantly lower, and dose-normalized AUC0–∞ was significantly higher, for dose level 3 than dose level 1. M-1 parameters were not significantly different between dose levels. No accumulation of pentoxifylline or M-1 was noted. Fifteen of 24 patients (63%) reported mild to moderate adverse events that may or may not have been treatment related. Frequency and severity did not differ significantly between dose levels. Conclusions: In the children in this study, pentoxifylline was well tolerated at the doses studied. No notable differences in clinical outcomes were observed between dose levels, and dose levels 3 and 4 (20 and 25 mg/kg daily, respectively) resulted in similar exposure to both pentoxifylline and M-1. Future efficacy and tolerability studies should use a daily dose of 20 mg/kg of pentoxifylline in acute KD.

Quinapril pharmacokinetics were studied in infants and children using a novel study design that allowed substitution of quinapril for one dose of the current chronic angiotensin-converting enzyme (ACE) inhibitor treatment. A total of 24 patients ranging in age from 2.5 to 82 months who were receiving an ACE inhibitor held their usual treatment on the study day and received a 0.2-mg/kg dose of quinapril syrup. Blood samples were collected through 24 hours postdose, and plasma was analyzed for quinapril and its active metabolite, quinaprilat. Quinapril was rapidly converted to quinaprilat. Quinaprilat concentrations generally peaked 1 to 2 hours postdose and declined with a mean half-life of 2.30 hours. Dosing on a mg/kg basis resulted in quinaprilat AUC and Cmax values that were generally comparable across the age range of patients in this study. The overall mean AUC0-infinity was 993 ng.h/mL (range: 533-1523), and mean Cmax was 260 ng/mL (range: 70.0-445.5). Quinaprilat CL/F correlated well with body size (body surface area or weight) and creatinine clearance (mL/min). Pharmacokinetic results after a 0.2-mg/kg dose in infants and children are comparable to those observed following a 10-mg dose in adults.

The pharmacokinetics of intravenous famotidine (0.5 mg/kg, maximum 20 mg) were evaluated in 18 pediatric patients (ages 1-18 years) with stable, chronic renal insufficiency. Subjects were stratified by calculated creatinine clearance (Clcr) into mild (Clcror = 50 to90 mL/min/1.73 m2), moderate (Clcror = 25 to50 mL/min/1.73 m2), and severe (Clcror = 10 mL/min/1.73 m2) renal insufficiency groups. Significant differences between the mild, moderate, and severe groups were found for elimination rate (Kel), apparent elimination half-life (t1/2), area under the curve (AUC), and total plasma clearance (Clp) (p0.01). Famotidine renal clearance (Clr) was found to be significantly different between the mild and severe groups (p0.05). A linear relationship was observed between Clcr and Clp (p0.0001; R2 = 0.70). No significant differences in nonrenal clearance (Clnr) were found between groups; however, Clnr as a percentage of Clp was significantly different in the severe group (92.9% +/- 7.3% Clnr) compared to the combined mild and moderate groups (21.9% +/- 45.6% Clnr) (p0.05). It was concluded that the pharmacokinetics of famotidine are significantly altered in children with chronic renal insufficiency; accordingly, dosing should be based on glomerular filtration rate (i.e., Clcr).

A case is presented of a breast-feeding mother receiving meropenem treatment for a postpartum urinary tract infection caused by extended-spectrum beta-lactamase producing Escherichia coli. Five milk samples were collected in a 48-hour period during meropenem therapy. The average and maximum meropenem concentrations in milk were 0.48 and 0.64 µg/mL, respectively. Based on the maximum concentration, the calculated infant daily exposure from breast milk was 97 µg/kg/d, and the infant weight-adjusted percentage of maternal dosage was 0.18%. There were no dermatologic or gastrointestinal side effects noted in the breastfed infant. Meropenem appears to be acceptable to use during breast-feeding.

Background: Depression is a common disorder in children and adolescents. It is often associated with psychologic distress, academic dysfunction, intrafamilial conflict, and the risk for suicide. For these reasons, safe and effective treatments are needed for depression in pediatric patients. Objective: This study considered the effectiveness of initiating the antidepressant paroxetine at a low dose and explored clinical and biochemical factors associated with response in juvenile depression. Methods: In this 8-week, single-center, open-label trial, children and adolescents with major depression were assessed weekly. Patients were initially treated with paroxetine at a dosage of 10 mg/d for 4 weeks. If a priori criteria for improvement were not met, the dosage of paroxetine was increased to 20 mg/d. Standard psychometric outcome measures were used. Prior to treatment, patients' phenotypes for cytochrome P450 2D6 and catechol O -methyltransferase activity were determined. Platelet-rich plasma serotonin was measured before and after 4 weeks of therapy. Plasma paroxetine concentration was measured after 4 weeks of treatment. Results: Thirty children and adolescents (15 boys, 15 girls) aged 6 to 17 years were enrolled and 29 were treated. Of the 27 patients who received at least 4 weeks of paroxetine treatment, 18 (66.7%) met improvement criteria at week 4. Open-label paroxetine was generally well tolerated and was associated with significant symptom amelioration by week 8 for most patients. Age, other demographic characteristics, and biochemical variables did not differ between the patients who had their dose of paroxetine increased and those who did not. Conclusions: The results of this study suggest that paroxetine 10 mg/d is effective in the open-label treatment of most depressed children and adolescents. For those who do not respond to this dosage, an increase to 20 mg/d appears to be an empirically supported treatment strategy.

To prospectively evaluate patient (parent), physician, and nurse satisfaction with antibiotics, 12,102 children in 661 pediatric study centers throughout the United States with infections to be treated on an outpatient basis were followed with questionnaires completed by parents and with interviews of patients and their parents. Comprehensive surveys were also completed by participating pediatricians and their nursing staffs of which 11,913 (98.4%) contained adequate information for inclusion in an analysis. Data were combined and analyzed using standard statistical methods. Loracarbef was perceived as being superior to other antibiotics based on cost, palatability, and dosing intervals. Few differences were seen among most antibiotics based on treatment outcome or adverse events. All antibiotics studied offered acceptable efficacy and were well tolerated as judged by physicians, nurses, parents, and children. Slight differences might result in increased compliance for some patients.

Dopamine and dobutamine are often infused together into acutely ill patients requiring temporary support of cardiac and renal function, but whether these catecholamines affect the metabolic clearance of each other is not established. We determined the kinetics of dopamine and dobutamine as substrates and inhibitors of each other, i.e., apparent V(max), K(m), and K(i), with crude preparations of human blood mononuclear cell catechol-O-methyltransferase (COMT) and platelet monoamine oxidase (MAO) at pH 7.4 and 37 degrees C. Values of V(max) for dopamine and dobutamine as substrates for COMT were 0.45 and 0.59 nmol of 3-O-methyl product formed per milligram of protein per minute, whereas those for K(m) were 0.44 and 0.05 mM, respectively. Dopamine and dobutamine were competitive inhibitors of each other in this reaction. The K(i) for dopamine as an inhibitor of dobutamine methylation was 1.5 mM, whereas that for dobutamine as an inhibitor of dopamine methylation was 0.015 mM. Dopamine but not dobutamine was a substrate for MAO. The V(max) for dihydroxyphenylacetaldehyde formation from dopamine was 0.29 nmol/mg protein/min and the K(m) for dopamine was 0.38 mM. Dobutamine was a noncompetitive inhibitor of dopamine oxidation in this reaction (K(i) congruent with 1.19 mM). The high apparent K(m) and K(i) values derived for dopamine and dobutamine when tested with these two human enzymes in vitro suggest that these catecholamines do not interfere with the metabolism of each other when both are infused together at therapeutic concentrations.

Objectives. Terbinafine has been shown to be effective in tinea capitis, using different treatment durations. However, no direct comparison of treatment duration has previously been investigated. This randomized, double-blind, parallel-group, multicenter study was designed to assess the effect of terbinafine treatment duration on the outcome of Trichophyton tinea capitis in a North American population. Methods. A total of 176 patients with a clinical diagnosis of tinea capitis were enrolled in this study and treated with oral terbinafine (3–6 mg/kg/d) for 1, 2, or 4 weeks. All patients were to be followed until week 12. A total of 159 patients had culture-confirmed tinea capitis attributable to Trichophyton species and constituted the intent-to-treat population used for efficacy analysis (50, 55, and 54 patients in the 1-, 2-, and 4-week arms, respectively). Results. At the end of study, effective treatment, defined as negative culture and low scores on signs and symptoms, was achieved in 56%, 69%, and 65% of patients who were treated with terbinafine for 1, 2, and 4 weeks, respectively. A negative culture was achieved in 60%, 76%, and 72%, respectively. Overall, the efficacy data showed that both the 2- and 4-week treatment regimens are clinically superior to the 1-week regimen. Terbinafine was well tolerated, and the incidence of adverse events showed no relationship to the duration of therapy. Conclusion. When efficacy, cost, and compliance are taken into consideration, 2 weeks of terbinafine therapy appears to be the optimal treatment duration for patients with Trichophyton tonsurans tinea capitis.