Centrally acting antihypertensives: not obsolete after all.

Centrally acting antihypertensive drugs, or sympatholytics, have a long history of efficacy, including some of the earliest major clinical trials, but they are now little used in the UK and elsewhere. This has been due to the introduction of new drugs with better tolerability than the centrally acting agents. In the case of clonidine there was also concern about rebound hypertension. However, at least some hypertensives may benefit from a centrally acting drug and a new class of agents, the imidazoline agonists, has recently been developed. One of these, moxonidine, is available in the UK. Clinical studies so far suggest that its efficacy is comparable to currently used drugs and that adverse effects are less severe than with earlier sympatholytics. Rebound hypertension has not been described, so this may lead to a revival in interest in these drugs as antihypertensive agents.