Principles of cancer pain management. Use of long-acting oral morphine.

Oral morphine is increasingly recognized as the pharmacologic standard for cancer pain management. Yet for the primary care physician and oncologist alike, misconceptions of the safety and efficacy of oral morphine along with lack of recognized guidelines for use have often resulted in inadequate cancer pain therapy. Use of controlled-release oral morphine sulfate (MSC) requires additional guidelines for optimum analgesia. Proposed are ten principles of dosing oral morphine, especially MSC, which were followed in a clinical trial involving cancer patients. MSC dosed at 8-, 10-, and 12-hour intervals was compared with immediate-release morphine (IRMS) dosed every four hours, and with prestudy analgesics. Patients achieved satisfactory analgesia at daily doses (mean +/- SE) of 118.0 +/- 8.6 mg and 111.4 +/- 12.6 mg (P greater than .05) for IRMS and MSC, respectively. Dosing endpoints were determined by titration with IRMS and MSC to a minimal and equivalent amount of supplemental short-acting analgesic. Side effects were typical for opioids and tolerated except for one dropout on IRMS (nausea and constipation). The ten principles have been incorporated into a dosing scheme as a practical guide for MSC therapy.