Orphenadrine poisoning in a child: clinical and analytical data

Orphenadrine is an anticholinergic drug used mainly in the treatment of Parkinson's disease. It has a peripheral and central effect and a known cardiotoxic effect when taken in large doses. We report the successful outcome of the treatment of a 2 1/2-year-old girl who accidentally ingested 400 mg of orphenadrine hydrochloride (Disipal). One hour after ingestion she presented neurological symptoms: confusion, ataxic walking, and periods of severe agitation. Generalized tonic-clonic seizures appeared resistant to the administration of multiple antiepileptics. They ceased after a supplementary dose of intravenous diazepam, endotracheal intubation, and mechanical ventilation. An episode of ventricular tachycardia responded well to i. v. lidocaine. Physostigmine was administered in three successive doses. The initial orphenadrine plasma level (3,55 microg/ml) was in the toxic range, associated with high mortality. The calculated elimination half-life was 10.2 h and the molecule and/or its metabolites were found up to 90 h after ingestion.