Methylnaltrexone could assist in treatment of opioid-induced constipation (OIC) after abdominal surgery, according to a recent study published in the American Journal of Cosmetic Surgery. The drug may offer an alternative to the current treatment protocol of stool softeners and bowel stimulants, which can cause bloating and discomfort for patients.
The drug, which goes by the trade name Relistor, has been used for years for OIC in terminal patients, but more recent studies have focused on its use in non-terminal patients. This study is one of the first to be performed on patients receiving temporary pain relief from opioid drugs.
The study included 26 patients, 13 each assigned to the control and treatment groups. All were female, between the ages of 30 and 55, and undergoing abdominoplasty. If a patient had not had a bowel movement by three days post-surgery, the control group was given magnesium citrate and the treatment group was given a 12 mg subcutaneous dose of methylnaltrexone.
The researchers found that the group treated with methylnaltrexone had a bowel movement about 24 hours post-treatment, as opposed to the standard group, who had one an average of 45 hours post-treatment, a statistically significant difference.
"There is a large amount of research out there regarding the effects of these types of drugs," says Talon Maningas, D.O., Maningas Cosmetic Surgery, Joplin, MO, an author on the study. "However, most of this is geared toward patients that require narcotic pain medications long-term, such as cancer patients. We wanted to evaluate how these medications affect individuals who are using narcotics in the short-term, such as postoperative patients, who experience the same symptoms associated with narcotic pain med use."
The drug reduces GI hypomotility, but does not have an effect on pain relief levels. It is normally given in subcutaneous form (used in the study) but is also available as an oral drug.
"This study looked at a medication that is delivered via a subcutaneous injection. An oral medication option would be much more convenient for our patients if it was proven to work as well," Dr. Maningas says.
As for future studies, "There are multiple opioid receptor antagonists available. I would like to see head-to-head studies evaluating the effectiveness between the different available routes of medication."