Purpose: A significant number of cancer patients will require an alternate route of morphine administration at some point during their illness. This study compared the clinical efficacy and safety of a novel morphine sulfate controlled-release suppository (MS-CRS) and subcutaneous (SC) morphine in patients with cancer pain.
Methods: Thirty patients with cancer pain were randomized in a double-blind crossover study to MS-CRS every 12 hours or SC morphine every 4 hours for 4 days each, using a 2.5:1 analgesic equivalence ratio. Pain intensity was assessed using a visual analog scale (VAS) and the Present Pain Intensity Index of the McGill Pain Questionnaire. Nausea and sedation were also assessed with a VAS. Evaluations were made by the patient at 8 AM, noon, 4 PM, and 8 PM and rescue morphine consumption recorded.
Results: Twenty-three patients completed the study (13 men and 10 women; mean age, 64.0 +/- 2.0 years) and were treated with mean daily MS-CRS and SC morphine doses of 326 +/- 69 mg and 138 +/- 28 mg, respectively. There was a small but significant difference in overall ordinal pain-intensity scores in favor of MS-CRS (0.7 +/- 0.1 v 0.9 +/- 0.1, P = .0459). There were no significant differences between MS-CRS and SC morphine in overall VAS scores for pain intensity (13 +/- 3 v 13 +/- 3 mm), sedation (23 +/- 3 v 25 +/- 4 mm), and nausea (8 +/- 2 v 9 +/- 2 mm). The mean daily rescue analgesic consumption during MS-CRS and SC morphine did not differ significantly (1.2 +/- 0.4 v 1.2 +/- 0.4 doses/d).
Conclusion: MS-CRS, administered every 12 hours, provides analgesia comparable to SC morphine and represents a reliable, noninvasive alternative method of pain control for patients unable to take oral morphine.