Extrapyramidal signs following zimelidine overdose.

A 35-year-old woman with depression attempted suicide by taking an overdose of zimelidine (5 g), which was confirmed by zimelidine and norzimelidine plasma levels. Physical examination and repeat EKGs performed 2, 6, 9, and 12 hours later showed no alteration in her level of consciousness and only a slight increase in QT duration. However, the patient exhibited a distinct extrapyramidal syndrome, a finding consistent with animal data suggesting that zimelidine may possess some dopamine-receptor blockade properties.