Evaluation of dosing guidelines for the use of oral controlled-release morphine (MS Contin tablets)

Based on clinical studies with the oral controlled-release morphine preparation, MS Contin tablets (MSC, Purdue Frederick, Norwalk, CT), a series of guidelines had been previously developed to help in titration of the medication. A multiinvestigator study was undertaken to prospectively evaluate these guidelines. Thus far, 66 patients have been enrolled and 47 have completed the study. Only three patients (5%) discontinued because of drug-related side effects. One group of patients (n = 28) as transferred to MSC from weak opioids because of inadequate pain control. The other group (n = 19) had previously received strong opioids. Each patient received MSC every 12 hours in accordance with specific dosing procedures designed to arrive at doses that would provide acceptable analgesia without unacceptable side effects. By the end of the study, approximately 75% of the patients achieved pain intensity scores indicating no or slight pain. However, since there were no dose-limiting side effects, it is probable that more patients could have achieved excellent analgesia if upward dose titration had continued. There was a broad range of individual total daily morphine requirements. The average daily morphine dose in the groups who had previously received weak and strong opioids was 110 mg and 200 mg, respectively. Side effects, although generally mild and few in number, appeared to have been inadequately treated in many cases. The results show that adherence to the guidelines results in effective pain management in the majority of patients. Additional issues include placing more emphasis on both rapid and complete dose titration and aggressive treatment of side effects, as well as exploration of the option of patient-controlled dose titration with MSC.