A comparative study of intramuscular buprenorphine and morphine in the treatment of chronic pain of malignant origin.

1 Twenty-seven patients with moderate to severe chronic pain of malignant origin received buprenorphine (0.3 mg) and morphine (10 mg) intramuscularly in a double-blind, single dose within patient study. 2 Efficacy analysis demonstrated no significant differences in the peak analgesic effects or in the time to reach these effects. However, buprenorphine had a significantly longer duration of action than morphine. 3 Sedation was the most frequent unwanted effect with a similar incidence following each treatment. Buprenorphine was associated with a significantly higher incidence, greater severity, earlier onset, and longer duration of dizziness, nausea and vomiting than morphine. 4 Following both treatments there were small but significant decreases in pulse rate, blood pressure, and respiratory rate.