Practical issues in drug selection and dosing.

Current guidelines recommend initiating antihypertensive therapy at a diastolic blood pressure greater than 90 mm Hg when nonpharmacologic measures have been unsuccessful. The risk of heart attack and stroke is increased regardless of whether the elevation of blood pressure is primarily systolic alone, diastolic alone, or both. In treating mild to moderate hypertension and in prevention and wellness programs in normotensive persons with a family history of the disease, the initial approach should be nonpharmacologic. Patients who remain hypertensive should proceed to drug therapy. Low-dose thiazide diuretics remain the preferred first step in elderly patients. In patients younger than age 40 years, especially those with tachycardia, a beta blocker may be used as the first step. Treatment should be initiated with less than a full dose, only proceeding to a full dose if necessary. If there is any appearance of extrasystoles, or a decrease in potassium levels to below 3.5 mEq/liter in the elderly, a potassium-sparing diuretic combination should be used. Although there is growing evidence that the effects of diuretic drugs on potassium may contribute to arrhythmias and sudden death, there is also increasing data suggesting that conserving electrolytes during diuretic therapy may obviate these ill effects.