the effect of disopyramide was compared to a pretreatment with one or several antiarrhythmic drugs ( quinidine , beta-blocking agents , verapamil , ajmalin-bitartrat , aprindine , propafenone , diphenylhydantoin ) which had been discontinued either due to ineffectiveness or the occurrence of intolerable side effects .
C0012702
disopyramide
C0003195
antiarrhythmic