Respiratory failure produced by severe procainamide intoxication in a patient with preexisting peripheral neuropathy caused by amiodarone.

We describe a patient in whom respiratory failure, due to extreme neuromuscular weakness, was produced by procainamide intoxication superimposed on a peripheral neuropathy secondary to long-term amiodarone therapy. Respiratory failure reversed rapidly after procainamide was discontinued, and the serum level fell to a therapeutic range.