Lomotil toxicity


  • Mixture of diphenoxylate / atropine used to treat diarrhea
  • Children are especially sensitive to toxicity (death reported after ingestion of <5 tablets)

Mechanism of toxicity

  • Diphenoxylate
    • opioid analog of meperidine, which has opioid-like toxicity in overdose
  • Atropine
    • anticholinergic effects
  • Toxic dose is variable

Clinical Features

  • Atropine effects
    • Lethargy, agitation, flushing, dry mucous membranes, mydriasis, ileus, tachycardia
  • Opioid effects
    • Miosis, coma, respiratory depression, respiratory arrest

Differential Diagnosis

Sedative/hypnotic toxicity

Anticholinergic toxicity Causes


  • Diagnosis is based on history and signs of toxicity



  • Pediatric patients should be observed in the ICU for 24 hours given risk of sudden respiratory arrest

See Also


  • Olson, K. Poisoning and Drug Overdose Clinical Manual. 2004