Acetylation is the major route of metabolism of many drugs including the antiarrhythmic agent procainamide. Coadministration of para-aminobenzoic acid was observed to decrease the biotransformation of procainamide to N-acetylprocainamide in a patient with rapid acetylation kinetics. In view of the distinct antiarrhythmic and toxic properties of procainamide and N-acetylprocainamide,the observed drug interference may have great clinical relevance in long-term oral antiarrhythmic therapy and in instances where other drugs converge for acetylation. © 1986, American College of Cardiology Foundation. All rights reserved.
Nylen, E. S., Cohen, A. I., Wish, M. H., Lima, J. J., & Finkelstein, J. D. (1986). Reduced acetylation of procainamide by para-aminobenzoic acid. Journal of the American College of Cardiology, 7(1), 185–187. https://doi.org/10.1016/S0735-1097(86)80280-7