Clinical Pharmacogenetics Implementation Consortium Guideline for NAT2 Genotype and Hydralazine Therapy

Hydralazine is a vasodilator typically used in the treatment of resistant hypertension and heart failure. N-acetyltransferase 2 (NAT2) catalyzes the metabolism of hydralazine into inactive metabolites. NAT2 poor metabolizers (historically referred to as "slow acetylators") are predicted to have increased plasma hydralazine concentrations compared with NAT2 rapid and intermediate metabolizers (historically referred to as "rapid acetylators" and "intermediate acetylators," respectively), which may lead to both increased clinical efficacy and adverse effects, including drug-induced systemic lupus erythematosus. This guideline summarizes the evidence from the literature relevant to NAT2/hydralazine and provides recommendations for hydralazine prescribing based on NAT2 genotype-predicted acetylator phenotype (updates at www.cpicpgx.org).