Hypertension medical therapy


 * ; Assistant Editor-In-Chief: Taylor Palmieri

Overview
There are many classes of medications for treating hypertension, together called antihypertensives, which by varying means act by lowering blood pressure. Evidence suggests that reduction of the blood pressure by 5-6 mmHg can decrease the risk of stroke by 40%, of coronary heart disease by 15-20%, and reduces the likelihood of dementia, heart failure, and mortality from vascular disease.

Medical Management
The aim of treatment should be blood pressure control to lower than 140/90 mmHg for most patients, and lower in certain contexts such as diabetes or kidney disease (some medical professionals recommend keeping levels below 120/80 mmHg). Each added drug may reduce the systolic blood pressure by 5-10 mmHg, so often multiple drugs are necessary to achieve blood pressure control.

Commonly used drugs

 * ACE inhibitors such as captopril, enalapril, fosinopril (Monopril), lisinopril (Zestril), quinapril, ramipril (Altace)
 * Angiotensin II receptor antagonists: eg, telmisartan (Micardis, Pritor), irbesartan (Avapro), losartan (Cozaar), valsartan (Diovan), candesartan (Atacand)
 * Alpha blockers such as doxazosin, prazosin, or terazosin
 * Beta blockers such as atenolol, labetalol, metoprolol (Lopressor, Toprol-XL), propranolol.
 * Calcium channel blockers such as nifedipine (Adalat®) amlodipine (Norvasc), diltiazem, verapamil
 * Direct renin inhibitors such as aliskiren (Tekturna)
 * Diuretics: eg, bendroflumethiazide, chlortalidone, hydrochlorothiazide (also called HCTZ)
 * Combination products (which usually contain HCTZ and one other drug)

Influence of age and race on medication efficacy

 * A randomized controlled trial by the Veterans Affairs Cooperative Study Group on Antihypertensive Agents reported the influence of patient age and race on the proportion of patients whose blood pressure was controlled by different agents.


 * For example:
 * Less than 7% of young white patients responded to a diuretic (hydrochlorothiazide)
 * Only 6% of older black patients responded to an ACE inhibitor (captopril)


 * The effect of age and race are in part due to differences in plasma renin activity.

Choice of initial medication
Which type of many medications should be used initially for hypertension has been the subject of several large studies and various national guidelines.

Regarding cardiovascular outcomes, the ALLHAT study showed a slightly better outcome and cost-effectiveness for the thiazide diuretic chlortalidone compared to other anti-hypertensives in an ethnically mixed population.

Whilst a subsequent smaller study (ANBP2) did not show this small difference in outcome and actually showed a slightly better outcome for ACE-inhibitors in older white male patients.

Whilst thiazides are cheap, effective, and recommended as the best first-line drug for hypertension by many experts, they are not prescribed as often as some newer drugs. Arguably, this is because they are off-patent and thus rarely promoted by the drug industry. Due to their metabolic impact (hypercholesterinemia, impairment of glucose tolerance, increased risk of developing Diabetes mellitus type 2), the use of thiazides as first line treatment for essential hypertension has been repeatedly questioned and strongly disencouraged.

Physicians may start with non-thiazide antihypertensive medications if there is a compelling reason to do so. An example is the use of ACE-inhibitors in diabetic patients who have evidence of kidney disease, as they have been shown to both reduce blood pressure and slow the progression of diabetic nephropathy. In patients with coronary artery disease or a history of a heart attack, beta blockers and ACE-inhibitors both lower blood pressure and protect heart muscle over a lifetime, leading to reduced mortality.

Advice in the United Kingdom
The risk of beta-blockers provoking type 2 diabetes led to their downgrading to fourth-line therapy in the United Kingdom in June 2006, in the revised national guidelines.

Advice in the United States
The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) in the United States recommends starting with a thiazide diuretic if single therapy is being initiated and another medication is not indicated.

African Americans
African-Americans respond well to hydralazine and nitrates. They often have low renin hypertension and do not respond well to ACE inhibitors and ARBs. They respond well to diuretics.

JNC- Seventh Report Recommendations: Medical Management
Table 1:Clinical trial and guideline basis for compelling indications for individual drug classes

Guidelines Resources

 * The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure


 * Treatment of Hypertension in the Prevention and Management of Ischemic Heart Disease : A Scientific Statement From the American Heart Association Council for High Blood Pressure Research and the Councils on Clinical Cardiology and Epidemiology and Prevention


 * 2007 Guidelines for the management of arterial hypertension: The Task Force for the Management of Arterial Hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC)