Antihypertensive therapy with calcium channel blockers in renal failure

There is convincing evidence that calcium channel blockers have protective effects on tissues like the myocard and the arterial vessel wall which exce ed the effects that can be expected from blood pressure reduction alone. Pa tients with renal failure are characterized by a markedly high prevalence o f hypertension, substantial structural alterations of the myocard and the a rterial vessel wall and thus by a high cardiovascular morbidity and mortali ty. Therefore calcium channel blockers could be particularly effective for the treatment of hypertension in patients with renal failure and reduce the ir cardiovascular mortality. This, however, could not be proven so far. On the contrary, an ongoing. debate on the use of calcium channel blockers in patients with cardiovascular disease has arisen a few years ago. Two large- scale studies in hypertensive patients with diabetes mellitus have shown ad verse effects of dihydopyridine-type calcium channel blockers on cardiovasc ular mortality as compared with angiotensin converting enzyme inhibitors. B esides their antiatherosclerotic effects, calcium channel blockers may also have nephroprotective actions. Some observations suggest a reduction of pr oteinuria in patients with diabetic nephropathy by non-dihydropyridine-type calcium channel blockers. A few observations indicate that also newer dihy dropyridine-type calcium channel blockers may be as effective in reducing t he progression of diabetic nephropathy as angiotensin converting enzyme inh ibitors. A prospective randomized study in hypertensive renal transplant pa tients receiving cyclosporine showed superior graft function in patients tr eated with nitrendipine as compared to placebo independent of the achieved blood pressure reduction. However, angiotensin converting enzyme inhibitors are considered as drugs of first choice for the treatment of hypertension in renal failure. Their beneficial effect on the progression of diabetic an d nondiabetic renal disease has been consistently shown in many studies. Al so the reduction of cardiovascular mortality by angiotensin converting enzy me inhibitors could be unequivocally demonstrated. For calcium channel bloc kers nephroprotective effects are less well established. Observations conce rning their effect on cardiovascular morbidity and mortality are equivocal. Recent studies indicate a particular efficacy of combination therapy with calcium channel blockers and angiotensin converting enzyme inhibitors in pa tients with renal failure. An additive nephroprotective effect of both drug classes may be expected. However, further studies are required to definite ly evaluate the role of calcium channel blockers and their combination with angiotensin converting enzyme inhibitors in patients with renal failure.