Blood Pressure & African Americans
Some Anti-Hypertensive Drugs Perform Better for Black People
Nov 12, 2007
African Americans experience higher rates of hypertension than non-Blacks. Doctors have an assortment of drugs to treat high blood pressure:
Types of hypertension drugs and their effectiveness in African Americans
- Diuretics—these are the mainstays of anti-hypertensive therapy and are the drug of first choice for many people with high blood pressure. Diuretics help the kidneys eliminate excess salt and water.Clinical results suggest that a diuretic often works just as well as the newer drugs in lowering blood pressure and is effective in preventing heart failure, heart attack, and stroke. Indeed, African-American patients, who are more likely to be salt-sensitive, respond as well as or better than Whites to diuretics. There are three classes of diuretics:
- Potassium-sparing diuretics: amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium).
- Thiazide diuretics: chlorothiazide (Diuril), chlorthalidone (Hygroton), indapamide (Lozol), hydrochlorothiazide (Esidrix, HydroDiuril), and metolazone (Mykrox, Zaroxolyn).
- Loop diuretics: bumetanide (Bumex), furosemide (Lasix), and torsemide (Demadex). Because loop diuretics act faster than thiazide and potassium-sparing diuretics, dehydration and potassium loss are possible outcomes.
The largest antihypertensive trial ever designed—ALLHAT—included a significant 35% black population. Of the 3 classes, the thiazide-type diuretic appeared to be superior in treating hypertension and preventing cardiovascular complication in Black patients. The study also seemed to confirm that control of blood pressure, especially in African-Americans, requires multiple drugs.
- Calcium channel blockers (CCBs): CCBs such as Procardia, Norvasc, Cardizem and others, help relax blood vessels. Used alone, they appear to be less effective than other drug classes in lowering blood pressure in African-Americans. Along with diuretics, CCBs, especially the long-acting version, may perform well.
- Angiotensin Converting Enzyme (ACE) Inhibitors (Capoten, Vasotec, Accupril, Zestril, etc.) generate nitric oxide in the wall of small arteries and enable blood vessels to remain relaxed, open and flexible. They apparently are much less effective when used alone, compared to diuretics, in lowering blood pressure and preventing stroke in African-American patients. Further, compared to Whites taking ACE inhibitors Black patients have a higher incidence of angioedema (rapid skin swelling) and cough.
- Beta blockers: African Americans respond less well to beta blockers such as Tenormin, Lopressor, Blocadren, etc. when used alone.
- Angiotensin receptor blockers (ARBs): (Atacand, Tevetan, Avapro, Mycardis, Diovan, Cozaar). African-American patients with hypertension have been shown to respond less favorably than white patients to ARBs.
- Direct Vasodilators: minoxidil, hydralazine (Apresoline), isosorbide dinitrate (Isordil, Sorbitrate) may release nitric oxide to relax the arteries and veins.
BiDil, a combination of the vasodilators hydralazine and isosorbide, is a heart failure drug aimed specifically at Blacks.
- New molecular entity (NME): Tekturna is the first high blood pressure drug approved by FDA that inhibits renin, a kidney enzyme associated with the regulation of blood pressure. African American patients tended to have smaller reductions in blood pressure than Caucasians and Asians, as is generally true for ACE inhibitors and ARBs—drugs that affect the renin-angiotensin system, a component of blood pressure regulation.
This information is not intended to replace medical advice one should obtain from his physician. Seek qualified medical advice for any issues relating to the treatment of hypertension.
Sources
Medscape Medscape Today, Medscape Family Medicine/Primary Care.
Morehouse School of Medicine, Emory University, and Association of Black Cardiologists, Inc.
Cardiovascular Research Institute, Morehouse School of Medicine
Journal of the American Academy of General Physicians
