Atypical Presentation of 4-Aminopyridine Overdose, ,

4-Aminopyridine (4-AP) is an investigational drug for the treatment of neurologic disorders including multiple sclerosis (MS). Until recently, relatively little was known about 4-AP toxicity in overdose; the only recorded cases involved neurologic symptoms ranging from mild parasthesias to tonic-clonic seizures. We report a case of accidental 4-AP overdose that resulted in continuous, dystonic, choreoathetoid-type movements that responded to treatment with standard anticonvulsant dosages of benzodiazepines. [Pickett TA, Enns R: Atypical presentation of 4-aminopyridine overdose. Ann Emerg Med March 1996;27:382-385.] The authors are grateful to Ritu Lal, MSc, and David Young, PhD, PharmD, at the Pharmacokinetics-Biopharmaceutics Laboratory, University of Maryland School of Pharmacy, Baltimore, for assaying our patientʹs serum 4-AP levels.