Isosorbide dinitrate and hydralazine hydrochloride: a review of efficacy and safety

In the USA alone, there are over 5,000,000 people diagnosed with heart failure. A disproportionate number of African-Americans are affected by this disease, with increased morbidity and mortality, yet they are tremendously under-represented in clinical trials. Several drugs have been approved for use in heart failure based on clinical trials, with percentages of African-American subjects as low as 1%. In the African-American Heart Failure Trial the use of BiDil, a drug combining isosorbide dinitrate and hydralazine hydrochloride, demonstrated a 43% decrease in overall mortality and a 39% decrease in first hospitalization. The combination consists of 20 mg of isosorbide and 37.5 mg hydralazine hydrochloride in a fixed dose that functions as a nitric oxide enhancer and an antioxidant, and helps to prevent tolerance to the prolonged use of nitrate. The hemodynamic effects of the combination drug in heart failure includes increased cardiac output. The US Food and Drug Administration approved the combination of isosorbide dinitrate based on the African-American Heart Failure Trial. Further clinical trials utilizing isosorbide dinitrate will hopefully determine the benefit of this combination in a larger population, including caucasians and other racial/ethnic groups.