Comparative efficacy of oral extended-release hydromorphone and immediate-release hydromorphone in patients with persistent moderate to severe pain: two randomized controlled trials.

Two multicenter, randomized, double-blind, crossover studies with identical designs evaluated the efficacy of oral extended-release hydromorphone (HHER) administered q24h compared with immediate-release hydromorphone (HHIR) dosed four times daily in patients with persistent moderate to severe pain. Patients titrated to a stable HHER dose were randomized to individualized doses of HHER or HHIR for 3 to 7 days before crossover to the second treatment. Primary efficacy end point was the mean of average pain intensity (API) scores, rated on a 0- to 10-point numeric scale, over the last 2 days before the pharmacokinetics/pharmacodynamics day of each double-blind period.