Surgical treatment of colorectal cancer is typically followed by several days of ileus, which may be exacerbated and prolonged by opioid medications such as morphine. It has been proposed that opioid receptor antagonists may counteract this effect of opioid drugs, allowing faster recovery of normal bowel function and potentially shortening hospital stays.

There is currently no approved treatment for postoperative ileus.

In an oral presentation on March 16^th, Eugene Viscusi, MD, director, acute pain management service, Jefferson Medical College, Philadelphia, Pennsylvania, United States, reported results from a double-blind, randomised, placebo-controlled trial of methylnaltrexone. The agent is selective for peripheral opioid receptors, so that it should not affect the central analgesic effects of opioid drugs.

The trial enrolled 66 patients who had undergone segmental laparoscopic colectomy and were randomised to placebo or methylnaltrexone at 0.30 mg/kg by 20-minute infusion every 6 hours for a maximum of 7 days. Treatment was ended earlier if the patient had tolerated solid food for 24 hours or was discharged from the hospital.

Mean time to first bowel movement after surgery occurred 20 hours faster with methylnaltrexone, Dr. Viscusi reported (98.0 vs. 118.1 hours, P = .038).

Discharge eligibility was achieved more than a full day sooner with the active drug (116.1 vs. 148.7 hours, P = .049).

Nonsignificant trends favouring methylnaltrexone were seen with other parameters, such as actual time to discharge and toleration of solid foods.

Dr. Viscusi said it was also notable that many more adverse events were seen in the placebo group, especially nausea and vomiting.

Methylnaltrexone was well tolerated, and hypotension was the only event reported more frequently compared with placebo.

Opioid doses and pain scores were similar in the 2 groups, which suggests that methylnaltrexone did not impair the efficacy of analgesis treatment.

Two phase 3 trials of methylnaltrexone are now underway, Dr. Viscusi said. The drug is under development by Progenics Pharmaceuticals.


[Presentation title: Methylnaltrexone Bromide Administered Postoperatively to Patients Following Segmental Colectomy May Accelerate GI Recovery and Hospital Discharge Without Affecting Opioid Analgesia. Abstract 15]

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