New classes of antihypertensive drugs and new findings with established agents

Research on antihypertensive drugs not only provides new information on presently used agents but also leads to the introduction of exciting new compounds. Several important clinical trials involving currently available drugs have been published recently. Angiotensin-converting enzyme inhibitors improved survival in patients with milder degrees of congestive heart failure, which indicates that they have become the cornerstone of treatment for this condition. Angiotensin-converting enzyme inhibitors delayed or prevented the development of diabetic proteinuria (> 200 micrograms/min) in a placebo-controlled randomized trial. Further, enalapril was more effective than metoprolol in reducing the rate of decline in renal function in patients with type I diabetes. Calcium channel blockers protected against acute renal failure in patients after renal transplantation in two separate studies. Calcium channel blockers were shown to promote natriuresis, with negative sodium balance the same as that associated with thiazide diuretics. The voltage-dependent calcium channel has been cloned, and the binding sites of the three classes of calcium channel blockers are now known. beta-Blockers and thiazide diuretics were the drug treatments in the Systolic Hypertension in the Elderly Program trial and in the Swedish Trial in Old Patients with Hypertension study (patients 65 to 85 years). In both investigations, stroke and cardiovascular events were significantly reduced by these conventional inexpensive agents. Clonidine was found to lower blood pressure primarily by its interaction with the imidazole receptor rather than the alpha 2 receptor. Elucidation of the imidazole receptor promises to shed light on physiologic mechanisms as well as lead to the introduction of new agents, such as moxonidine.(ABSTRACT TRUNCATED AT 250 WORDS)