Opioid-Induced Bowel Dysfunction

Abstract

Opioid-induced bowel dysfunction is a distressing condition that may persist indefinitely in the clinical setting. As we understand more about normal gastrointestinal (GI) physiology, we are also beginning to understand more fully how opioids cause bowel dysfunction. Current therapeutic interventions for opioid-induced bowel dysfunction can be burdensome and sometimes lack efficacy. Systemic opioid antagonists administered orally can induce laxation, but can unpredictably induce systemic or local GI tract withdrawal symptoms. Two new investigational agents, alvimopan and methylnaltrexone, are peripherally acting opioid antagonists that do not cross the blood-brain barrier. Studies to date show promise that these agents may relieve opioid-induced bowel dysfunction in a well-tolerated manner without reversing central analgesia.

(451) Efficacy and safety of methylnaltrexone for opioid-induced constipation in patients with chronic noncancer pain: a placebo crossover analysis

“…Opioids can interfere with normal GI motility, thereby reducing productive peristalsis, increasing fluid absorption from the GI tract, and decreasing intestinal secretions, which leads to drier harder stool. 3 Subcutaneous methylnaltrexone has been shown in an RCT to be well tolerated and to provide significant relief from OIC when administered once daily or every other day for the treatment of OIC in patients with chronic noncancer pain. 18 The current post hoc analysis examined the repeatability of these findings by evaluating the tolerability and response of patients who were initially treated with placebo during the RCT and crossed over to treatment with methylnaltrexone 12 mg prn for up to 12 weeks.…”

“…1,2 Opioids disrupt peristalsis, which also results in increased fluid absorption and drier stool and inhibition of GI secretions. 3 Many patients develop some degree of opioid-induced constipation (OIC), 4,5 and unlike other GI-related adverse effects (eg, nausea), patients typically do not develop tolerance to OIC across time, or they develop tolerance very slowly. 6,7 Severe OIC may result in opioid dose reduction or limitations on upward titration, potentially affecting adequate pain control.…”

Pain Management

“…Stool softeners such as docusate work by drawing water into the stool making it softer and thus require adequate fl uid intake to be effective. Although commonly prescribed, effi cacy of stool softeners as single agents in opioid-induced constipation is poor; thus, they should be used in combination with laxatives (Thomas 2008 ). Similar to stool softeners, fi ber bulking agents draw and maintain water in stool, allowing multiple bowel movements to pass.…”

Therapie der opioidinduzierten Obstipation

“…Häufig auftretende Nebenwirkungen der Therapie sind hierbei, neben meist passageren Beschwerden wie Übelkeit, Erbrechen, Harnverhalt und Atemdepressionen, vor allem gastrointestinale Beschwerden im Sinne einer schwer zu beherrschenden und oftmals ganz erheblichen Obstipation [1]. Diese Komplikation, die bis zum paralytischen Ileus reichen kann, wird hierbei allerdings nicht nur durch die Opioide selbst induziert, sondern kann durch begleitende Erkrankungen, wie Dehydrierung, oder auch parenterale Ernährung oder maschinelle Beatmung verstärkt werden [2].…”

“…Alternativ verwendete und stimulierende Laxanzien wie Senna oder Bisacodyl können nach Entfaltung ihrer Aktivität schmerzhafte abdominelle Krämpfe induzieren, wohingegen gasproduzierende, zuckerbasierte osmotische Laxanzien unangenehme Blähungen hervorrufen [1]. Systemische Opioidantagonisten, die wie Naloxon auch die Blut-Hirn-Schranke passieren, können zwar ebenfalls die Darmtätigkeit wieder anregen, jedoch treten häufig schwer vorherzusehende Entzugssymptome oder Schmerzen auf [8].…”