The pharmacokinetics of oxycodone and its metabolites following single oral doses of Remoxy®, an abuse-deterrent formulation of extended-release oxycodone, in patients with hepatic or renal impairment.

OBJECTIVE: Remoxy® (Pain Therapeutics, Inc., Austin, TX) is an abuse-deterrent formulation of extended-release oxycodone. The effects of renal or hepatic impairment on the pharmacokinetics (PK) of single, oral doses of Remoxy 20 or 10 mg, respectively, were assessed in two phase 1 studies in subjects aged 18-80 years. METHODS: PK parameters included maximum plasma concentration (C(max)) and area under the concentration-time curve from time 0 to the last quantifiable concentration (AUC(0-t)), and extrapolated to infinity (AUCinf). Adverse events (AEs) were monitored. RESULTS: Mean (SD) oxycodone Cmax values following Remoxy 20-mg administration were 17.6 (9.1), 21.9 (11.2), 25.9 (18.2), and 31.6 (14.5) ng/mL and AUC0-t values were 210.7 (82.1), 271.6 (83.3), 299.5 (76.3), and 493.5 (175.9) ng·h/mL in subjects with normal or mild (n = 6 each), moderate (n = 5), and severely impaired renal function (n = 6), respectively. Mean (SD) oxycodone Cmax following Remoxy 10-mg administration was 7.6 (3.3), 7.8 (2.3), and 13.1 (5.3) ng/mL and AUC(0-t) was 105.7 (49.5), 134.7 (38.3), and 218.0 (74.1) ng·h/mL in subjects with normal, mild, and moderately impaired hepatic function (n = 6 each), respectively. Differences in exposure values between the different renal and hepatic groups were significant. Treatment-emergent AEs were reported by 14.3, 66.7, 66.7, and 50.0 percent of subjects with normal, mild, moderate, and severely impaired renal function, respectively, and by 50.0, 33.3, and 66.7 percent of subjects with normal, mild, and moderately impaired hepatic function, respectively. CONCLUSIONS: As renal or hepatic function decreased, oxycodone Cmax and AUC(0-t) were up to approximately twofold higher following single, oral doses of extended-release Remoxy. AEs were those typically reported for opioids. Lower doses of Remoxy may thus be safely prescribed to subjects with renal or hepatic impairment.

Peroxisome proliferator-activated receptors α and γ are linked with alcohol consumption in mice and withdrawal and dependence in humans.

BACKGROUND: Peroxisome proliferator-activated receptor (PPAR) agonists reduce voluntary ethanol (EtOH) consumption in rat models and are promising therapeutics in the treatment for drug addictions. We studied the effects of different classes of PPAR agonists on chronic EtOH intake and preference in mice with a genetic predisposition for high alcohol consumption and then examined human genomewide association data for polymorphisms in PPAR genes in alcohol-dependent subjects. METHODS: Two different behavioral tests were used to measure intake of 15% EtOH in C57BL/6J male mice: 24-hour 2-bottle choice and limited access (3-hour) 2-bottle choice, drinking in the dark. We measured the effects of pioglitazone (10 and 30 mg/kg), fenofibrate (50 and 150 mg/kg), GW0742 (10 mg/kg), tesaglitazar (1.5 mg/kg), and bezafibrate (25 and 75 mg/kg) on EtOH intake and preference. Fenofibric acid, the active metabolite of fenofibrate, was quantified in mouse plasma, liver, and brain by liquid chromatography tandem mass spectrometry. Data from a human genome-wide association study (GWAS) completed in the Collaborative Study on the Genetics of Alcoholism (COGA) were then used to analyze the association of single nucleotide polymorphisms (SNPs) in different PPAR genes (PPARA, PPARD, PPARG, and PPARGC1A) with 2 phenotypes: DSM-IV alcohol dependence (AD) and the DSM-IV criterion of withdrawal. RESULTS: Activation of 2 isoforms of PPARs, α and γ, reduced EtOH intake and preference in the 2 different consumption tests in mice. However, a selective PPARδ agonist or a pan agonist for all 3 PPAR isoforms did not decrease EtOH consumption. Fenofibric acid, the active metabolite of the PPARα agonist fenofibrate, was detected in liver, plasma, and brain after 1 or 8 days of oral treatment. The GWAS from COGA supported an association of SNPs in PPARA and PPARG with alcohol withdrawal and PPARGC1A with AD but found no association for PPARD with either phenotype. CONCLUSIONS: We provide convergent evidence using both mouse and human data for specific PPARs in alcohol action. Reduced EtOH intake in mice and the genetic association between AD or withdrawal in humans highlight the potential for repurposing FDA-approved PPARα or PPARγ agonists for the treatment of AD.