Comparison of i.v. quinidine and disopyramide.

procainamide.We clearly showed in dogs1 and have recently confirmed in man2 that the two drugs have different electrophysiologic effects.Woosley et al.3 have recently reported that antiarrhythmic response to one drug does not necessarily mean response to the other.Thus, just because a patient responds to procainamide there is absolutely no guarantee that that patient will respond to NAPA, because the drugs probably have different mechanisms of action.To date there are only a small number of publications in relatively small numbers of patients indicating that NAPA is an efficacious antiarrhythmic agent.We would prefer to await the results of further clinical trials which might help to establish its appropriate role as an antiarrhythmic agent before recommending its widespread use.