The patient burden of opioidinduced bowel dysfunction

Sofie Hyldahl, Debbie Gronlund, Asbjorn Mohr Drewes & Christina Brock*

Orally formulated opioids are commonly prescribed analgesics to treat severe pain. Among severe adverse effects are respiratory depression, sedation and opioid-addiction; less dangerous, however still burdensome for the many treated patients, are symptoms such as nausea, cognitive impairment and bowel dysfunction. It has e.g. been shown that the patient experienced burdens of opioid induced bowel dysfunction (OIBD) and opioid induced constipation (OIC) negatively impact the quality of life of these patients. Consequently, patients often take less medication than prescribed to dampen these adverse effects. This review focuses a thorough description of the underlying mechanistic causes of OIBD, originating from binding of exogenous opioids to the peripheral opioid receptors in the enteric nervous system of the gut. Consequently, the bowel becomes dysfunctional function changes caused by alterations in i) motility, ii) secretion and absorption and iii)sphincter functions. Such alterations lead to a variety of symptoms including gastro-esophageal reflux, abdominal pain, prolongation of transit times and dry hardened stool. Thus, the experienced psychological burden of opioid-induced bowel dysfunction is a net-result of its physical occurrence as well as its negative impact on health-related quality of life. Unfortunately, gastrointestinal dysfunction is considered a taboo and people may refrain to describe and discuss the experienced burdens. This review targets health care professionals, who to a higher degree are encouraged to discuss openly if presence of OIBD/OIC impacts the daily life and social activities of the patients. Finally, different mechanistic treatment approaches are reviewed in order to provide clinicians with different pharmacological options and strategies, which include traditional laxatives, prokinetics and co-administration of opioid antagonists. Even though the opioid-antagonists have proved to be superior to placebo in the relief of OIBD/OIC, further clinical studies are needed in order to optimize treatments for the benefit of future patients.