Narcotic bowel syndrome (NBS) is a subgroup of opioid bowel dysfunction characterized by chronic or frequently recurring abdominal pain that worsens with continued or escalating doses of opioids. While they may look helpful at first, over time the pain-free periods become shorter and tachyphylaxis occurs, leading to increasing opioids doses. Ultimately, increasing dosages increase the adverse effects on pain sensation and delayed motility, thereby initiating the development of NBS.
Although pain is the dominant feature, nausea, bloating, intermittent vomiting, abdominal distension and constipation are common.
The syndrome can occur in patients with no prior gastrointestinal disorder who receive high dosages of opioids after surgery or acute painful problems, among patients with functional GI disorders or other chronic gastrointestinal diseases who are managed by physicians unaware of the hyperalgesic effects of chronic opioids.
It is basic to the diagnosis of NBS is the recognition that chronic or escalating doses of opioids lead to continued or worsening symptoms rather than benefit.
Moreover, the symptoms are nonspecific, and many clinicians are unaware that narcotic medications can actually sensitize patients to the experience of pain. Thus, continued treatment with opioids lead to a vicious cycle of pain, increasing the doses of and continued or worsening pain. The most perplexing feature of the NBS is to recognize and accept that opioid analgesics can actually cause or aggravate
(¿hyperalgesia and tolerance?) the actual pain that is being treated.
Treatment involves early recognition of the syndrome, an effective physician patient relationship, graded withdrawal of the opioids according to a withdrawal protocol and the institution of medications to reduce removal effects. It can be initiated when the diagnosis is made and there is reasonable evidence that no other diagnosis explains the symptoms. NBS is a positive diagnosis which occurs independent of other pathological conditions, and it may also be the cause of pain in patients with existing inactive abdominal pathology.
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Adapted from Grunkemeier DMS et al. The narcotic bowel syndrome: clinical features, pathophysiology and management. Clinical Gastroenterology and Hepatology, 2007, Vol. 5 Issue 10