LAS VEGAS — Currently approved agents for opioid-induced constipation in this country include lubiprostone, methylnaltrexone, and naloxegol, with the last two belonging to the category of peripherally acting mu-opioid receptor antagonists (PAMORAS), according to speakers who presented on opioid-induced constipation earlier this week.
Charles E. Argoff, MD, professor of neurology at Albany Medical College; Jeffrey A. Gudin, MD, clinical instructor of anesthesiology at Mount Sinai University School of Medicine; and Anthony J. Lembo, MD, associate professor of medicine and director of the GI Motility Laboratory at Harvard Medical School hosted the interactive session, which was jointly provided by Global Education Group and Integritas Communications and supported by an educational grant from AstraZeneca.
Dr. Argoff said that in addition to the approved medications, there are several medications in the experimental phase that address opioid-induced constipation as well. Research into this topic is critical, he said, because opioid-induced constipation is a such a commonly reported adverse event, affecting up to 50% of patients on long-term therapy.
In addition to staying on top of the latest treatment options, the panel stressed the importance of being informed about their patients’ bowel movements.
To discuss constipation with patients, clinicians and providers must first have a clear idea of what defines constipation. According to the OIC Multidisciplinary Working Group, constipation is defined as a change from baseline bowel habits that is characterized by any of the following: reduced bowel movement frequency, development or worsening of straining to pass bowel movements, a sense of incomplete rectal evacuation, and harder stools.
According to the presentation, one in every 3 patients on opioids do not discuss their constipation with their clinician because they are embarrassed or worried that the opioid treatment will be reduced or discontinued.
Risk factors for constipation include: female gender, advanced age, dehydration, nutritional deficits, drug issues, and in the case of patients taking opioids, medication type and strength.
Both Dr. Argoff and Dr. Gudin offered some clinical pearls for assessing patients on longer-term opioids for constipation. They directed the audience to www.exchangecme.com/oic2015 for a patient education tool kit and patient conversation guide, as well as other clinical practice tools. The key, Dr. Argoff said, is “beginning the conversation with your patients.”
The speakers advised clinicians to ask patients: “How many bowel movements are you having per week, how many rolls of toilet tissue are you using, and how many cans of Lysol are you using?”
Dr. Gudin explained that there are several tools available to help patients and clinicians communicate clearly about stools, including the Bristol stool form scale, which was developed in the late 1990s and asks patients to point to one of 7 types of stools; the bowel functional index tool; and the Pac-sym, which is a questionnaire designed to assess bowel movement history, as well as current bowel movements.
Dr. Gudin said in addition to regularly assessing patients’ bowel movements, guidelines on long-term opioid therapy recommend that all patients be advised on a prophylactic bowel regimen, including adequate dietary fiber and water intake, as well as regular exercise and laxatives.
“Patients who receive prophylactic therapy are less likely to experience constipation,” Dr. Gudin said.