A fifteen-fold edrophonium overdose [abstract] Abstract uri icon
  • Introduction: Edrophonium chloride is a reversible acetylcholinesterase inhibitor primarily used in the diagnosis of myasthenia gravis. Toxicity from therapeutic doses of edrophonium has been reported for decades; however, no case report of human overdose exists. We report a case of an accidental fifteen-fold overdose of edrophonium.
    Case report: A 73-year-old female was scheduled for an edrophonium (Enlon®, Tensilon®) test to confirm the diagnosis of myasthenia gravis. The patient was to receive 2 mg of edrophonium chloride, followed by another 8 mg, to reach a total of 10 mg. The patient accidentally received 20 mg as an initial dose. When the patient showed no improvement in dysphagia and other symptoms, the remainder of the vial, containing 130 mg of edrophonium, was administered. The total 150 mg dose of edrophonium was delivered IV within 1 minute. Immediately after the second dose, the patient complained of difficulty breathing and suffered a respiratory arrest. Atropine 1 mg IV was given resulting in a successful resuscitation. No hypersalivation was noted. The patient awoke, followed commands, and heart rate accelerated to 150’s bpm. Within minutes, apnea, bradycardia, and loss of pulse recurred, but responded to epinephrine and atropine. Because of cardiopulmonary instability, she was endotracheally intubated. Approximately 20 hours post exposure, she was extubated and remained alert and neurologically intact. Vital signs were normal except for mild hypertension with BP = 147/64 mmHg.
    Discussion: Edrophonium chloride is a reversible acetylcholinesterase inhibitor and has been reported to cause bradycardia, dyspnea, and even respiratory arrest at therapeutic doses. The patient we report experienced all symptoms listed above with a fifteen-fold overdose, but fully recovered with supportive measures.
    Conclusion: Despite well known side effects at therapeutic doses and the manufacturer’s recommendations for having atropine at the bedside, surprisingly, no actual human overdose of edrophonium has been reported. This is the first reported case, to our knowledge, of an overdose of edrophonium, and the patient recovered without any sequelae.

  • publication date
  • 2009
  • Research
  • Drugs and Drug Therapy
  • Emergency Medicine
  • Medication Errors
  • Poisoning
  • Additional Document Info
  • 47
  • issue
  • 7