Controlled release morphine tablets: a double-blind trial in patients with advanced cancer.

Eighteen of 27 patients with pain due to advanced cancer, completed a randomised crossover comparison of 4-hourly aqueous morphine sulphate and twice daily controlled release morphine tablets. There was no difference between the two regimens in analgesic efficacy or adverse effects, but there was an apparent improvement in quality of sleep on the controlled release tablets. After completion of the study, 17 patients continued with the latter medication for periods that ranged from 2 days to 94 weeks (median 6.5 weeks). Controlled release morphine tablets given twice daily provide a simpler and more convenient treatment regimen than a 4-hourly opioid for patients with cancer pain, once they have been stabilised.