Misdiagnosis of a Mexiletine Overdose Because of a Nonspecific Result of Urinary Toxicologic Screening

To the Editor: It has been suggested that toxicologic screening rarely leads to changes in medical management in the emergency department. 1 We present a case of an overdose that was misdiagnosed because of the nonspecific nature of an immunoassay. A 17-year-old boy was brought to the hospital in status epilepticus. His glucose and electrolyte levels were normal; he had a serum ethanol level of 14.2 mmol per liter. He was treated with repeated intravenous doses of diazepam and phenytoin. The seizures subsided after 1 hour, but he continued to experience agitation and hallucinations, which gradually subsided over the next 24 . . .