Hydralazine Pharmacology

Hydralazine, branded as Apresoline, functions as a direct-acting vasodilator that stimulates arterioles to lower blood pressure. While effective for hypertension, its clinical utility is often limited by a short half-life requiring frequent three-to-four-times-daily dosing, which negatively impacts patient adherence compared to once-daily alternatives. Beyond hypertension, it serves as an off-label treatment for reduced ejection fraction heart failure, particularly when combined with nitrates for patients who cannot tolerate ACE inhibitors or for those of African descent who may show diminished responses to standard pathways. A critical clinical consideration is the rare, dose-dependent risk of drug-induced lupus erythematosus, characterized by fever and joint pain and identified through elevated anti-nuclear antibody (ANA) titers. Management requires careful monitoring for additive hypotensive effects when combined with drugs like sildenafil or Parkinson’s medications, as well as potential opposition from NSAIDs and stimulants.