This randomized, open-label, crossover study investigated the influence of food on the pharmacokinetics of extended-release hydromorphone in 30 healthy volunteers. Participants received extended-release hydromorphone 16 mg in the fasted state and immediately after a high-fat breakfast. In addition, the pharmacokinetics of a 16-mg dose of extended-release hydromorphone and a 16-mg daily dose (4 mg qid) of immediate-release hydromorphone in the fasted state were compared. Treatments were separated by washout periods of 7 to 14 days. Naltrexone was given throughout each treatment period to block the opioid effects of hydromorphone. The 90% confidence intervals (CIs) of the ratios of geometric means for maximum plasma concentrations (C(max)) and area under the plasma concentration-time curve (AUC) for extended-release hydromorphone in the fed and fasted states were within the bioequivalence criteria range of 80% to 125%. In the fasted state, the 90% CIs of the ratios of AUC geometric means for extended-release hydromorphone and immediate-release hydromorphone were also within the bioequivalence range. Both hydromorphone treatments were well tolerated. This study shows that the bioavailability of extended-release hydromorphone is not affected by food and that the bioavailability of extended-release hydromorphone under fasting conditions is comparable with that of the immediate-release formulation when administered at the same total daily dose.

The steady-state pharmacokinetics of an extended-release formulation of hydromorphone, OROS® hydromorphone, was investigated in a randomized, openlabel, crossover study in healthy volunteers. Participants were randomly assigned to receive 16 mg of OROS hydromorphone once daily and 4 mg of immediaterelease hydromorphone four times daily for five consecutive days. The two treatments were separated by a washout period of 7-14 days. Naltrexone was given throughout both treatment periods to block the opioid effects of hydromorphone. Steady-state hydromorphone concentrations were statistically analyzed using Helmert contrasts to determine when steady state was reached. A total of 30 participants were enrolled, of whom 29 completed both treatment periods. The two treatments produced comparable steady-state plasma drug concentrations, but peakto-trough fluctuations were smaller with OROS hydromorphone (61 percent vs 172 percent) in comparison with immediate release hydromorphone. Overall systemic exposure to hydromorphone was similar between the two formulations. The ratio of the geometric means between the two formulations for the area under the concentration-time curves at steady state was 105.2 percent with a 90% confidence interval (CI) of 99.8-110.8 (geometric mean: 102.7 percent; 90% CI: 97.6-108.2 after correcting for measured drug content), which was within the bioequivalence range (80-125 percent). The analysis of Helmert contrasts showed that steadystate conditions were attained by day 4. Both treatments were well tolerated. This study shows that OROS hydromorphone maintains steady-state plasma drug concentrations within the same range as immediate-release hydromorphone at the same total daily dose, with less fluctuation.