Pentamorphone for management of postoperative pain

The efficacy, duration, and safety of the synthetic opioid pentamorphone in the treatment of acute postoperative pain were evaluated in a randomized, double-blind study of 72 patients given 0.08, 0.16, or 0.24 μg/kg of pentamorphone or a placebo intravenously in the recovery room after major abdominal or orthopedic surgery. Only patients given 0.24 μg/kg of pentamorphone experienced decreased pain intensity and increased sedation, both transient in duration. Although the two higher doses of pentamorphone delayed the patient's request for supplemental morphine, the total amount of morphine required within the first hour was not different between treatments. No acute cardiorespiratory changes were observed. Pentamorphone (0.08-0.24 μg/kg) was ineffective for treating acute postoperative pain after major surgery.