Table 1. Pharmacokinetic Indices after Administration of Immediate- and Sustained-release Hydromorphone

Data are mean ± SD or median and interquartile range. First- and last-time plasma concentration (Cp) > 50% peak indicates when at least 50% of the peak concentration was detected in plasma for the first and for the last time, respectively. Duration Cp > 50% peak Cp indicates time span that plasma concentration was greater than 50% of the peak concentration.

* Results regarding effect-site concentrations are provided in the text.

†P < 0.05 among all treatments.

‡P < 0.05, immediate-release hydromorphone (IRH) differed significantly from all other treatments, but different doses of sustained-release hydromorphone (SRH) were not significantly different among each other.