Amiodarone interaction with lidocaine.

We report a case of lidocaine toxicity with seizures that appears to represent a drug interaction with amiodarone. A toxic lidocaine level and reduced lidocaine clearance were documented 65 h after amiodarone was added to the treatment regimen. This is the first report of increased levels and serious clinical toxicity of lidocaine due to amiodarone. The mechanism appears to be altered hepatic metabolism of lidocaine caused by amiodarone.