Predictions for the future of antihypertensive drug therapy

Treatment of hypertension is changing rapidly because drugs with greater specificity are being developed and knowledge is evolving concerning factors that determine responses to available drugs. For almost a decade US physicians have relied on national guidelines called Stepped-Care. Step 1 calls for using either a diuretic or a beta blocker; in subsequent steps other drugs are added. Because of the new drugs and the new knowledge it is likely that Step 1 will soon be broadened to include many other drugs. The short-term changes in Step-1 will be based upon those factors now known to influence pressure responsiveness: age--young vs old; race--black vs white; type--renovascular vs essential; and severity--mild-to-moderate vs severe. In young hypertensives, much evidence suggests a dominant neurogenic component of central origin; therefore, a central sympatholytic drug or an alpha-beta receptor blocker seem to be preferable as firstline drugs. Hypertension, primarily systolic, in elderly patients responds well to diuretics or calcium channel blockers. Mild-to-moderate hypertension in blacks is particularly responsive to diuretics, while beta blockers are relatively ineffective. Renovascular hypertension is predominantly caused by increased angiotensin II, so converting enzyme (ACE) inhibition is indicated in unilateral stenosis. The hallmark of severe hypertension is vasoconstriction, so a vasodilator (nifedipine, minoxidil, or an ACE inhibitor) is indicated as first treatment, not a diuretic or a beta blocker alone. Long term changes will depend on development of drugs with specificity for newly, or better defined, pressor mechanisms.