Hydralazine, sold under the brand name Apresoline among others, is a medication used to treat high blood pressure and heart failure.

[9] The sympathetic stimulation may increase heart rate and cardiac output, and in people with coronary artery disease may cause angina pectoris or myocardial infarction.

To prevent these undesirable side effects, hydralazine is usually prescribed in combination with a beta blocker (e.g., propranolol) and a diuretic.

[11] Hydralazine is commonly used in combination with isosorbide dinitrate for the treatment of congestive heart failure in black populations.

[12] It should not be used in people who have tachycardia, heart failure, constrictive pericarditis, lupus, a dissecting aortic aneurysm, or porphyria.

[13] Common (1–10% frequency) side effects include flushing, hypotension, anginal symptoms, aching or swelling joints, muscle aches, positive tests for atrial natriuretic peptide, stomach upset, diarrhea, nausea and vomiting, and swelling (sodium and water retention).

The molecular mechanism involves inhibition of inositol trisphosphate-induced Ca2+ release from the sarcoplasmic reticulum in arterial smooth muscle cells.