Control of cancer-related pain with MS Contin: a comparison between 12-hourly and 8-hourly administration.

Nineteen cancer patients with chronic pain of moderate to severe intensity were randomized in a double-blind manner to 5 days of either 8-hourly or 12-hourly administration of controlled-release morphine (MS Contin, MSC), followed by the alternate schedule for 5 days. The control of pain, using an average dose of 303.4 +/- 254.4 mg/day of MSC, was good during both the 8-hourly and 12-hourly phases, and the mean daily pain intensity measured by visual analogue scale (VAS), pain relief (VAS), and global efficacy scores did not differ when compared by treatment schedule. The need for supplemental "rescue" morphine was infrequent and did not differ between treatment phases (8-hourly, 0.7 +/- 0.7 and 12-hourly, 0.6 +/- 0.6 doses per day, p = 0.6232). The overall frequency and severity of adverse events did not differ between the two dosing schedules. A majority of patients (67%) reported that they believed that 12-hourly dosing was a moderate or great advantage over 8-hourly dosing.