Alvimopan, a peripherally acting opioid antagonist, reduces the length of hospital stay after a bowel resection, a new study indicates.
Linda W. Banares, PharmD, currently a postgraduate year two (PGY2) ambulatory care pharmacy resident at Parkland Health and Hospital System in Dallas, Texas, presented results of a 2009 medication- use study she and her colleagues conducted while she was a PGY1 pharmacy resident at the Moses Cone Health System (MCHS) in Greensboro, North Carolina. The MCHS is a multihospital, community-based system that performs roughly 500 bowel resections annually.
Alvimopan speeds recovery of bowel function after partial bowel resection. In August 2008, alvimopan was added to the health system's formulary with restrictions. At the request of the MCHS Pharmacy & Therapeutics Committee, Banares and her group performed a 6-month evaluation to assess the appropriate use of alvimopan and to track clinical outcomes in 142 patients who either did or did not receive alvimopan.
Most patients undergoing abdominal or pelvic surgery experience delayed gastrointestinal recovery, including postoperative ileus, Banares noted. Postoperative ileus is characterized by lack of passage of flatus and an absence of bowel movements along with abdominal pain, distension, nausea, vomiting, and accumulation of gas or fluids in the bowels. Postoperative ileus may occur for a variety of reasons, including surgical trauma, inflammation, and the use of exogenous opioids to manage pain.
Although metoclopramide, erythromycin, and other drugs have some gutstimulatory effect, none of these agents have demonstrated efficacy in reducing the duration of postoperative ileus, Banares noted. Alvimopan is currently the only US Food and Drug Administration-approved medication indicated to accelerate the time to gastrointestinal recovery following partial large or small bowel resection with primary anastomosis. Phase 3 clinical trials demonstrated reduced time to recovery by up to 1 day.
In the present study, all patients were scheduled for partial large or small bowel resection with primary anastomosis via an open or laparoscopic technique. The main indication for surgery was colon cancer. Patients in the alvimopan group received 12 mg preoperatively and twice daily postoperatively until hospital discharge or for a maximum of 7 postoperative days. Patients in the control group underwent surgery before the drug was commercially available.
The study found that after adjustment for sex and age, the mean postoperative length of stay was 1.2 days shorter in the alvimopan group undergoing open resection and 0.9 days shorter in the group undergoing laparoscopic resection, for a cost-saving of $1042 and $338, respectively, per patient.
Alvimopan tended to have a more pronounced effect in patients 70 years of age or older, but the difference between older and younger patients was not significant.
There were no cases of myocardial ischemia or sudden death in the alvimopan group.
In the United States, approximately 350,000 patients undergo colorectal or small bowel resection each year, Banares observed. "Based on the efficacy, safety, and economic benefit seen in this study, alvimopan appears to have a role in clinical care pathways for open and laparoscopic bowel resection," she said.