Dextromethorphan abuse masquerading as a recurrent seizure disorder

Area of Science:

• Emergency Medicine
• Clinical Toxicology
• Neurology

Background:

• Dextromethorphan (DXM) is an antitussive agent increasingly subject to abuse.
• DXM toxicity can present with symptoms mimicking other conditions, complicating diagnosis.
• Accurate identification of DXM abuse is essential for patient management in emergency departments.

Observation:

• A young woman presented with recurrent episodes initially diagnosed as seizures.
• Initial evaluations, including neuroimaging and toxicology screens, were unremarkable.
• Subsequent presentation revealed horizontal nystagmus and tachycardia, prompting further inquiry.

Findings:

• The patient admitted to chronic Dextromethorphan abuse.
• Serum DXM levels were significantly elevated (988.3 ng/mL), far exceeding therapeutic ranges.
• The patient experienced complete recovery after a brief hospital admission.

Implications:

• Dextromethorphan abuse should be considered in the differential diagnosis of new-onset seizures, especially in young adults.
• Unique toxicological profiles of abused substances like DXM necessitate specific diagnostic considerations.
• Early recognition and intervention for DXM toxicity can prevent misdiagnosis and ensure appropriate patient care.