Adverse reactions to procainamide.

1 Data from a comprehensive drug surveillance programme are analysed to provide details of procainamide use and toxicity in medical wards of teaching hospitals in five countries. 2 Out of a total of 488 recipients 9.2% had one or more adverse effect attributed to the drug; common effects being arrhythmias, gastro-intestinal upsets and drug fever. Although occasionally of major severity, no patient died as a consequence of procainamide toxicity. 3 Toxicity was directly related to total daily dose and duration of hospitalization but was not related to age, weight of the patient or presenting urea or albumin concentrations.