All-cause mortality imbalance in the tigecycline phase 3 and 4 clinical trials.

In 12 of 13 phase 3 and 4 comparative clinical trials, all-cause mortality was higher in the tigecycline group versus the comparator group. Study-level mortality risk differences were pooled using a random-effects meta-analysis. Statistical models evaluated the association between patient-level all-cause mortality and baseline factors using logistic regression, recursive partitioning [classification and regression tree (CART) analysis] and survival techniques.

Population pharmacokinetics of atorvastatin and its active metabolites in children and adolescents with heterozygous familial hypercholesterolemia: selective use of informative prior distributions from adults.

The population pharmacokinetics (PPK) of atorvastatin and its principal active metabolite, o-hydroxyatorvastatin, were described in 6-17 years old pediatric hypercholesterolemia patients with a 2-compartment model for both parent and metabolite. Informative prior distributions on selected parameters, based on adult data, were required to stabilize the model and were implemented using a Bayesian penalty term on the likelihood function in the nonlinear mixed effects model (NONMEM VI with PRIOR). Concentrations below the limit of quantitation were treated as censored data using a conditional likelihood function.

Bioequivalence of long half-life drugs--informative sampling determination--using truncated area in parallel-designed studies for slow sustained-release formulations.

A simulation study was done to determine if 72 h is the most informative sampling duration for bioequivalence (BE) determination in parallel-designed BE studies with drugs that have half-lives of at least 30 h. The impact of absorption and elimination half-lives on informative sampling was evaluated. Two-treatment parallel-designed BE studies using a one-compartment oral absorption model with half-lives of 30 and 350 h was simulated.

Dose-escalating study of the pharmacokinetics and tolerability of fesoterodine in children with overactive bladder.

Objective: To determine the pharmacokinetics, safety and tolerability of fesoterodine, and assess the utility of 3-day bladder diaries (exploratory objective) in pediatric subjects with neurogenic detrusor overactivity or idiopathic overactive bladder (OAB).

Methods: In this 8-week open-label study, subjects (8-17 years, >25 kg) received fesoterodine 4 mg for 4 weeks, then 8 mg for 4 weeks. Blood samples were obtained at weeks 4 and 8.

Modeling dose-response relationships of the effects of fesoterodine in patients with overactive bladder.

Background: Fesoterodine is an antimuscarinic for the treatment of overactive bladder, a syndrome of urgency, with or without urgency urinary incontinence (UUI), usually with increased daytime frequency and nocturia. Our objective was to develop predictive models to describe the dose response of fesoterodine.

Methods: Data from subjects enrolled in double-blind, placebo-controlled phase II and III trials were used for developing longitudinal dose-response models.

The effect of azithromycin on ivermectin pharmacokinetics--a population pharmacokinetic model analysis.

Background: A recent drug interaction study reported that when azithromycin was administered with the combination of ivermectin and albendazole, there were modest increases in ivermectin pharmacokinetic parameters. Data from this study were reanalyzed to further explore this observation. A compartmental model was developed and 1,000 interaction studies were simulated to explore extreme high ivermectin values that might occur.

Population pharmacokinetics of oxycodone in children 6 months to 7 years old.

Young children are often undertreated for pain. One barrier to effective pain treatment is understanding the pharmacokinetic behavior of analgesics in this age group. Oxycodone is a commonly prescribed opioid for severe pain, yet little is known about its pharmacokinetics in young children.

Clinical pharmacology and pharmacokinetics of once-daily hydromorphone hydrochloride extended-release capsules.

Hydromorphone hydrochloride extended release (HHER) is a multiparticulate melt-extrusion pellet capsule formulation administered q24h. Study 1 investigated the bioavailability of 24-mg HHER fed, as well as 24-mg and 12-mg HHER and 8-mg hydromorphone hydrochloride immediate-release (HHIR) tablets fasting. No clinically significant food effect was observed on hydromorphone C(max) or AUC for the 24-mg HHER, and dose proportionality (AUC) was demonstrated between 12- and 24-mg HHER.