Medical management of opioid-induced constipation differs from other forms of condition

Traditional laxatives are recommended as first-line agents to treat patients with a confirmed diagnosis of opioid-induced constipation (OIC), according to a new guideline from the American Gastroenterological Association (AGA). If an adequate trial of laxatives results in suboptimal symptom control, the guidelines recommend peripherally-acting mu-opioid receptor antagonist (PAMORA) drugs, namely naldemedine, naloxegol and methylnatrexone. This class of drugs has shown to improve bowel symptoms without compromise to pain relief, although there can be associated side effects, including diarrhea and abdominal pain. The new guideline¹ and accompanying technical review² have been published in Gastroenterology, the official journal of the AGA Institute.

"Opioid overuse has become a public health crisis in America. What the public often doesn't hear about are just how common gastrointestinal side effects, especially constipation, are in opioid users," says Seth D. Crockett, MD, MPH, lead author of the guideline, University of North Carolina School of Medicine, Chapel Hill. "Physicians have struggled with treating this condition due to previous lack of clinical guidance. The new AGA guideline clarifies existing data and provides clear direction for physicians on how to best treat opioid-induced constipation."

Opioid-induced constipation is estimated to affect 40 to 60 percent of patients taking chronic opioid therapy. Estimates now show that up to 5 percent of Americans are currently taking opioids regularly.

The term opioid-induced constipation (OIC) refers to constipation that is a result of using opioids. A consensus definition is, "a change when initiating opioid therapy 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, or harder stool frequency." ?

For medical management of OIC, the guideline recommends:

• Start with traditional laxatives as first-line agents.
• In patients who don't respond to traditional laxatives, AGA recommends naldemedine over no treatment.
• In patients who don't respond to traditional laxatives, AGA recommends naloxegol over no treatment.
• In patients who don't respond to traditional laxatives, AGA suggests methylnatrexone over no treatment.

The new AGA clinical guideline on medical management of opioid-induced constipation presumes that patients have been appropriately diagnosed and that they have either a prolonged requirement or dependence on opioids. Nevertheless, one of the first steps for physicians managing patients with OIC is to ensure they are on the lowest possible dose of opioids needed. There may also be benefit in "opioid switching" to a less constipating formulation. This guideline focuses on the medical management of OIC. Therefore, it does not address the role of psychological therapy, alternative medicine approaches, surgery or devices.