Central and peripheral blockade of the sympathetic nervous system.

Agents that work primarily by inhibiting effects of the sympathetic nervous system continue to be widely used for the therapy of hypertension. There are two principal types of drugs: those that work in the central nervous system, and those that act primarily at peripheral neuromuscular sites. Both types of drugs are often effective as single-agent therapy although they also work well in combination with diuretics and other antihypertensive agents. Recently, there has been interest in a new transdermal method for administering the centrally-acting drug clonidine; the consistency of the plasma drug concentrations achieved by this form of treatment appears to minimize adverse effects while providing continuous therapeutic efficacy. Interest is also focusing on the ability of sympathoinhibitory agents such as alpha-methyldopa to produce regression of left ventricular hypertrophy, possibly by mechanisms independent of their antihypertensive action.