Calcium antagonists and acute renal failure

PURPOSE: To critically review the question of whether calcium antagonists can prevent or attenuate post-ischemic acute renal failure (ARF). PATIENTS AND METHODS: Using a computer-assisted search, we identified all experimental and clinical studies published in English between 1980 and 1988 in which the main research question addressed the efficacy of verapamil, diltiazem, or nifedipine in the treatment of post-ischemic ARF. Studies were then selected for review based on clearly specified inclusion criteria and evaluated against accepted methodologic guidelines. RESULTS: In experimental studies of warm renal ischemia, calcium antagonists provided significant protection of glomerular filtration rate (GFR) when given before and after ischemic injury; however, isolated pre- or post-ischemic treatment produced equivocal results. In autotransplantation studies on protracted cold ischemia, verapamil produced a modest, although physiologically significant, increase in GFR during warm reperfusion but failed to alter graft survival. Studies of calcium antagonists in humans with ARF have been confined to patients undergoing renal transplantation. Diltiazem given both to donor grafts and to recipients produced a significant reduction in the rate of delayed graft function but failed to improve one-year graft survival. This result may be due to the study of small numbers of low-risk patients. At present, there is no conclusive evidence that one calcium antagonist is more efficacious than another in the treatment of post-ischemic ARF. CONCLUSIONS: Calcium antagonists appear to prevent or reduce the severity of post-ischemic ARF only when given prior to and after the ischemic insult. As a result, these agents will have most utility in the setting of renal transplantation. Although the efficacy of these agents in reducing delayed graft function appears to be established, their failure to improve graft survival is poorly understood and requires further investigation.