Efficacy of oxycodone hydrochloride controlled-release tablets for titration in treating moderate to severe cancer pain: a prospective, multicenter, randomized, parallel, controlled study

Objective To evaluate the effect of oxycodone hydrochloride controlled-release tablets for titration in treating moderate to severe cancer pain in a prospective, multicenter, randomized, parallel, controlled study. Methods Hospitalized cancer patients with moderate to severe pain, aged 18-64 yr, weighing 48-69 kg, with numerical rating scale(NRS)score ≥ 4 points, were divided into 4 groups according to the multicenter stratified block randomization: naive IR group, naive CR group, tolerant IR group, and tolerant CR group.A 72-h rapid titration protocol was adopted, the initial dosage: immediate-release morphine tablets 10 mg in naive IR group, oxycodone hydrochloride controlled-release tablets 10 mg in naive CR group, and 10% of the total equivalent dosage of immediate-release morphine tablets (total opioids dosage) used the day before oral administration in tolerant IR group, 10% of the total equivalent dosage of oxycodone hydrochloride controlled-release tablets (total opioids dosage)used the day before oral administration in tolerant CR group.Titration method: pain assessment was performed every hour after administration until patients went to bed; when the NRS score was increased and ≥7 points, the equivalent immediate-release morphine tablet dose was increased by 100% than the previous dose; when the NRS score was not increased but still ≥7 points, the equivalent immediate-release morphine tablet dose was increased by 50% than the previous dose; when the NRS score was 4-6 points, the equivalent immediate-release morphine tablet dose was the same as before; when the NRS score was decreased and ≤3 points, patients were continuously observed without additional medication.Maintenance method: after the end of titration, the total amount of immediate-release morphine tablets for titration was converted into an equivalent dose of oxycodone hydrochloride controlled-release tablets and was given once a day for 2 days in naive IR and tolerant IR groups; the initial dose of oxycodone hydrochloride controlled-release tablets plus the total amount of immediate-release morphine tablets for titration was converted into an equivalent dose of oxycodone hydrochloride controlled-release tablets and was given once a day for 2 days in naive CR group and tolerant CR group.When break-through pain occurred, immediate release morphine tablets 5-10 mg was taken orally to record administration, degree of pain relief, dose of oxycodone hydrochloride controlled-release tablets used, titration cycle and amount, and the effective analgesia and adverse reactions were recorded. Results Compared with naive IR group, the titration cycle and total titration dose were significantly reduced, the rate of effective analgesia was increased, the degree of pain relief was better, the frequency of oral morphine tablets was reduced, and the dosage of oxycodone hydrochloride controlled-release tablets used was decreased in naive CR group (P 0.05). Conclusion Oxycodone hydrochloride controlled-release tablets for titration provide better efficacy in treating moderate to severe cancer pain. Key words: Oxycodone; Pain; Cancer