Background: There have been case reports and basic science studies demonstrating the efficacy of naloxone as a reversal agent for loperamide overdose. We report the youngest human with loperamide-induced coma, respiratory depression, and ileus; all successfully reversed with administration of naloxone. Case report: A 14 day old male was given a 1mg PO dose of loperamide for diarrhea, and was given another 1mg 7 hours later. He was brought to the emergency department for evaluation shortly thereafter due to his lethargic nature. He was unarousable and apneic in the emergency department and was endotracheally intubated and admitted to the ICU. He then developed an ileus, with no bowel sounds and no passage of gas or stool. A 0.1mg/kg intravenous bolus of naloxone was administered and the child became arousable. He would have been extubated immediately if the providers would have had a naloxone infusion ready. An intravenous naloxone infusion was subsequently started, and they extubated him 2 hours later. He had no further respiratory depression. The providers also noted return of bowel sounds shortly after the naloxone administration, as well as passage of gas and stool. The naloxone drip was continued for 72 hours and the patient had an uneventful remainder of his hospital course.
Case discussion: Loperamide is a xenobiotic marketed for its antidiarrheal effect. It is contraindicated in infants under the age of 24 months. 1mg PO is the dose recommended for infants over two years of age and 13kg of weight. This patient met neither of those criteria. Loperamide acts as an agonist at multiple opioid receptors (mainly mu), and can cause a clinical profile of an opioid overdose. Naloxone efficacy has been shown to reverse the side effects of loperamide. There are published reports of naloxone use in newborns to reverse the effects of xenobiotics other than loperamide.
Conclusion: This patient is the youngest reported to have loperamide-induced coma, respiratory depression, and ileus reversed with naloxone. Loperamide can cause a life threatening side effect profile in overdose of a 2 week-old infant. Naloxone can be used as an effective reversal agent in the case of a loperamide overdose at this young age.