Opioid-induced bowel dysfunction (OIBD) is an increasing problem due to the common use of opioids for pain worldwide. It is a pharmacologically induced condition: opioid receptors are throughout the gastrointestinal tract and when stimulated by exogenous opioids, produce changes in sphincter function and motility, secretion, and absorption of fluids that are reflected in clinical symptoms.
These changes express with different symptoms, such as dry mouth, gastroesophageal reflux, vomiting, bloating, abdominal pain, anorexia, hard stools, constipation, and incomplete evacuation.
Opioid-induced constipation (OIC) is probably the most prevalent symptom, however OIBD has an excess of symptoms, many of which look like other conditions.
• Patients suffering chronic constipation or irritable bowel syndrome with constipation for long periods of time are susceptible to increased complaints when initiate opioid treatment.
• Gastroduodenal ulcerations induced by non-steroidal anti-inflammatory drugs (NSAIDs) may trigger the nausea, pain or vomiting.
• Patients with gastroesophageal reflux disease may experience worsening of symptoms
• Intestinal obstruction due to tumors can mimic symptoms of severe constipation and cause other abdominal complaints.
• Nausea may be caused by intracranial pathology, including tumors.
• The “narcotic bowel syndrome” is characterized by chronic or intermittent abdominal pain, which often increases in severity despite continued or escalating doses of opioids.
First-line treatment of OIC is conventional laxatives, lifestyle changes, decreasing the opioid dosage and alternative analgesics. Whilst opioid rotation may also improve symptoms, these remain unalleviated in a substantial proportion of patients.
Should conventional treatment fail, mechanism-based treatment with opioid antagonists should be considered, and they show advantages over laxatives.
It should not be ignored that many causes for OIBD exist, which should be taken into consideration in the individual patient.
See reference for details.
Adapted from Drewes AM et al. Definition, Diagnosis and Treatment Strategies for Opioid-Induced Bowel Dysfunction—Recommendations of the Nordic Working Group. Scandinavian J Pain 2016; 11: 111–122.