A COMPARISON OF REGULARLY DOSED ORAL MORPHINE AND ON-DEMAND INTRAMUSCULAR MORPHINE IN THE TREATMENT OF POSTSURGICAL PAIN

A randomized, placebo-controlled, double-blind clinical trial was cond ucted to compare the use of regularly dosed po morphine and on-demand im morphine in 47 patients undergoing total hip arthroplasty. Patients were randomized to receive either 20 mg (initial dose) of regularly d osed morphine (every four hours po) plus breakthrough pain medication on-demand consisting of both 10 mg morphine po and placebo im, or an e quivalent regularly dosed oral placebo (every four hours) with breakth rough pain medication consisting of oral placebo and 5-10 mg morphine im. Subsequent to each request for breakthrough pain medication, the n ext regularly dosed oral solution was increased by 5 mg (or equilvalen t volume of placebo) to a maximum of 40 mg po Q4H. Time-averaged pain scores were lower on both postoperative day 1 and 2 in the group recei ving regularly dosed morphine po (P < 0.05). Fewer patients requested breakthrough pain medication on both days in the oral morphine group. The incidences of nausea and vomiting, and of decreased respiratory ra tes were similar in both groups. Regularly dosed oral morphine is inex pensive and should be compared to other methods of opioid delivery.