Dyspepsia and Opioid–Induced Bowel Dysfunction: The Role of Opioid Receptor Antagonists

Opioid analgesics are commonly and in most cases effectively used to manage chronic pain of moderate to severe intensity. Apart from analgesia, opioids exert numerous adverse ef‐ fects, several of which impact the gastrointestinal (GI) tract. The chronic use of opioid anal‐ gesics in fact is commonly associated with adverse effects on the gastrointestinal tract. [1] Opioid–induced bowel dysfunction (OIBD) comprises gastrointestinal symptoms such as dry mouth, anorexia, gastroesophageal reflux (GERD), delayed digestion, abdominal pain, flatulence, bloating, nausea, vomiting, and constipation with hard stool and incomplete evacuation. Further, side effects from long–term opioid therapy may result in more serious intestinal complications such as faecal impaction with overflow diarrhea and incontinence, pseudo–obstruction (causing anorexia, nausea and vomiting), disturbance of drug absorp‐ tion, and urinary retention and incontinence. OIBD may also lead to inappropriate opioid dosing and in consequence, insufficient analgesia. As a result, OIBD significantly deteriorate patients’ quality of life and compliance with their treatment. Approximately one-third of pa‐ tients treated with opioid analgesics do not adhere to the prescribed opioid regimen or sim‐ ply quit the treatment due to OIBD symptoms [2].