There are many types of medications used to treat high blood pressure. The medications are classified as follows:

• Angiotensin-converting enzyme inhibitors, or ACE inhibitors, block the production of a body chemical that constricts the arteries. ACE inhibitors include benazepril hydrochloride, enalapril maleate and quinapril hydrochloride.
• Angiotensin-II receptor blockers hinder the effect of a body chemical that constricts the arteries. This group of medications includes valsartan, losartin potassium and candesartan.
• Beta-blockers lower the heart rate and increase the amount of blood pumped with each heartbeat. Common beta-blockers include atenolol, propanolol hydrochloride and nadolol.
• Calcium-channel blockers lower the heart rate and relax the blood vessels. Some common calcium-channel blockers include amlodipine besylate, diltiazem hydrochloride, nifedipine and verapamil.
• Diuretics, or water pills, help the body get rid of extra fluid and sodium. Common diuretics include furosemide, hydrochlorothiazide and chlorthalidone.
• Sympathetic nerve inhibitors keep the nervous system from constricting arteries. This group includes clonidine hydrochloride, guanabenz acetate and alpha methyldopa.
• Vasodilators relax the muscles in the blood vessel walls and allow the vessels to dilate. Common vasodilators include isosorbide dinitrate and hydralazine.

If you doctor has prescribed drugs to control your high blood pressure, find out what you should know about your medication in the Drug Reference Center. Or if you're concerned about possible drug interactions visit our Drug Interaction Center.