Side effects of vasodilator therapy.

Vasodilating antihypertensive drugs have in common the capacity to activate the peripheral sympathetic nervous system through the carotid sinus baroreceptor reflex mechanism, thereby increasing heart rate, renin release, and sodium and water retention. They differ in their tendencies to augment cardiac output and to relieve or precipitate cardiac failure and arrhythmias. Vasodilating antihypertensive drugs can produce an array of side effects and toxicity including headache, facial changes, hair growth, varying degrees of sodium and water retention, and rarely systemic lupus erythematosus and allergic reactions. Detailed knowledge of these effects is a prerequisite to skillful individualization of antihypertensive regimens.