Renal protection with the calcium antagonists

In addition to their role as highly potent antihypertensive drugs, calcium antagonists may also play an important future role in the area of tissue protection and preservation. Calcium antagonists exert favorable effects on renal hemodynamics related to their reversal of renal vasoconstrictors. Calcium antagonists are also capable of blocking intracellular calcium overload induced by various types of ischemic or toxic stimuli. Features such as these may be of substantial value in ameliorating acute renal insufficiency secondary to renal ischemia, iodinated radiographic contrast agents, or the administration of various nephrotoxic drugs. The latter includes agents such as the aminoglycoside antibiotics, cyclosporine A, and the cancer chemotherapeutic agent cisplatin. Recent prospective, controlled studies from our group indicate that calcium antagonists protected against postischemic acute renal failure in the setting of cadaveric renal transplantation. Moreover, in a prospective, randomized, controlled clinical trial, we were able to demonstrate that the prophylactic use of nitrendipine reduced the decrease in GFR in patients receiving radiographic contrast agents. Calcium antagonists may also play a beneficial role in preventing progressive renal disease. Data from a number of studies conducted in experimental animals, as well as information from clinical trials, support such a view. Although the mechanisms of action of calcium antagonists in the setting of chronic renal failure are not yet fully established, their beneficial effects may be related to protective actions such as the reduction in renal hypertrophy, modulation of mesangial cell uptake of macromolecules, changes in permselectivity of the glomerulus, and a decreased free radical formation. These various aspects will be the topic in this review.