Clinical observations on controlled-release morphine in cancer pain

The authors report the data from two studies on the use of controlled-release morphine sulphate tablets for cancer pain relief. This preparation allows just two administrations per day, in comparison with immediate release oral aqueous morphine solution. The first study, a randomized trial carried out on 70 patients suffering from advanced cancer pain, evaluated the analgesic efficacy and side effects of this drug. The second, an open study of 113 patients, assessed analgesic efficacy, incidence of side effects, and the effects of age on dose. The analgesia provided by controlled-release morphine administration proved to be superimposable to those of the oral aqueous morphine solution. Moreover, the use of controlled-release morphine was associated with a statistically significant reduction of some side effects. Ninety-one percent of patients needed controlled-release morphine every 12 hr, while 9% required it every 8 hr.