Dosage range study of morphine sulfate controlled-release

The purpose of this study was to assess the efficacy and side effects of morphine sulfate controlled-release (MSCR) in patients with cancer pain who had previously required narcotic analgesia. The study design included an attempt at conversion of 30 patients from the previously required narcotic analgesic to around the clock (ATC) 4-h dosing of morphine sulfate immediate-release (MSIR) that would provide satisfactory analgesia. All patients controlled on MSIR at 4-h ATC were then successfully converted to MSCR and had an appropriate dosage regimen established. The patients were subsequently maintained for 4 weeks on MSCR, with the majority of patients adhering to a 12-h schedule at two-thirds the total daily morphine dose of the q 4 h regimen. Twenty-four patients completed this dosage range study. Five dropouts were not related to use of MSCR, while one patient was discontinued because of nausea following administration of both MSIR and MSCR. Patients preferred the analgesic relief of MSCR over their previous narcotic regimen. Half the patients manifested fewer side-effects compared with their prestudy narcotics. No patients had greater side-effects with MSCR. These findings support the efficacy and safety of MSCR at appropriate dosage for the prolonged relief of cancer pain.