Are antihypertensive drugs similar in protecting the kidney?

Elevated systemic blood pressure is associated with more rapid progression of renal failure, as recently documented by prospective observations. Intervention studies with antihypertensive medication have clearly documented that progression can be attenuated by antihypertensive medication. Experimental studies and, more recently, controlled prospective trials in humans, have provided evidence that in this respect angiotensin converting enzyme (ACE) inhibitors are superior to equipotent doses of alternative antihypertensive agents, suggesting a specific nephroprotective action. Experimental studies suggest that this is not only due to hemodynamic, but also to nonhemodynamic, mechanisms. The effect of calcium channel blockers on this progression is less uniform and may depend on the model used, the percentage of blood pressure lowering, and possibly also the type of calcium channel blocker. Despite some discrepancies in experimental studies, recent controlled clinical trials show a similar slowing of progression with either ACE inhibitors or calcium channel blockers. Since combination therapy is required in most patients with advanced renal failure, recent experimental studies on development and glomerular sclerosis and clinical studies showing at least additive effects on reduction of proteinuria independent of blood pressure argue for combining ACE inhibitors and calcium antagonists.