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Hypertension is recognized as a major risk factor for several potentially lethal cardiovascular conditions, including myocardial infarction, heart failure, and stroke. Guidelines urge more active prevention and treatment of hypertension. According to the guidelines, average systolic pressure greater than 120 but less than 130 mm Hg is considered elevated, pressure equal to or greater than 130/80 but less than 140/89 mm Hg is considered stage 1 hypertension, while pressures equal to or greater than 140/90 mm Hg are considered stage 2 hypertension. Increased systolic pressure is now considered at least as important as elevated diastolic. Both stage 1 and stage 2 hypertension are deserving of treatment in most patients and the guidelines urge that causes and treatment of atherosclerosis also be considered (see Chapter 35).
Many drugs are available for treatment of hypertension and in most patients blood pressure can now be controlled effectively and with minimal adverse effects. Antihypertensive drugs are organized around a clinical indication—the need to treat the disease—rather than a single receptor type. The drugs covered in this unit have a variety of mechanisms of action including diuresis, sympathoplegia (interference with the sympathetic nervous system), vasodilation, and antagonism of the renin-angiotensin-aldosterone system, and many agents are available in most of these categories.
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