Fixed-Dose Versus Off-Label Combination of Isosorbide Dinitrate Plus Hydralazine Hydrochloride: Retrospective Propensity-Matched Analysis in Black Medicare Patients with Heart Failure

Introduction Based upon the findings of the African-American Heart Failure Trial, the US Food and Drug Administration approved the fixed-dose combination of isosorbide dinitrate (ISDN) and hydralazine hydrochloride (HYD) (FDC-ISDN/HYD) as a new drug for treatment of heart failure (HF) in self-identified African Americans. According to the FDA, FDC-ISDN/HYD has no therapeutic equivalent. However, off-label combinations of the separate generic drugs ISDN and HYD (OLC-ISDN+HYD) or isosorbide mononitrate (ISMN) and HYD (OLC-ISMN+HYD) are routinely substituted without any supporting outcome data. We conducted an exploratory retrospective propensity-matched cohort study using Medicare data to determine whether a survival difference exists between these treatments in medication-adherent patients.