Dextromethorphan Overdose with Refractory Status Epilepticus and Reversible Cranial Nerve Reflex Loss: A Case Report

Area of Science:

• Pharmacology
• Toxicology
• Neurology

Background:

• Dextromethorphan is a common antitussive medication with a generally safe profile at recommended doses.
• Overuse of dextromethorphan can lead to severe adverse effects, but detailed case reports with pharmacokinetic data are limited.
• Understanding severe overdose scenarios is critical for clinical management and patient safety.

Purpose of the Study:

• To report a rare case of massive dextromethorphan overdose with detailed pharmacokinetic analysis.
• To investigate the clinical presentation and management of severe dextromethorphan toxicity.
• To elucidate the role of dextromethorphan versus its metabolite, dextrorphan, in overdose toxicity.

Main Methods:

• A case report of a 21-year-old female patient with schizophrenia who ingested a large quantity of dextromethorphan.
• Clinical observation and intensive supportive care, including endotracheal intubation and anticonvulsant therapy.
• Serial serum concentration monitoring of dextromethorphan and dextrorphan.

Main Results:

• The patient presented with refractory status epilepticus and reversible cranial nerve reflex loss after ingesting 20,280 mg of dextromethorphan.
• Serum dextromethorphan levels were significantly elevated, while dextrorphan levels remained within therapeutic range.
• The patient stabilized and recovered fully with intensive care, with no long-term sequelae.

Conclusions:

• Massive dextromethorphan overdose can result in severe, potentially fatal neurological complications, including status epilepticus.
• Pharmacokinetic data suggest dextromethorphan itself, not its metabolite, is primarily responsible for the toxicity in such cases.
• Effective management relies on intensive supportive care, and factors affecting metabolism can influence outcomes.