Occlusive atherosclerosis is a major cause of morbidity and mortality in renal transplant recipients. Hyperlipidemia associated with the transplanted state may be at least partially responsible for this complication and is therefore an important target of therapy. The 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors are powerful cholesterol-lowering drugs, but their broad use in transplant recipients has been hindered by concerns about interactions with cyclosporine. Cyclosporine interferes with the elimination of these agents, increasing their plasma and tissue levels and predisposing the patient to rhabdo-myolysis. Fluvastatin, the first entirely synthetic HMG-CoA reductase inhibitor, possesses a distinct pharmacologic profile, including a shorter half-life and virtually no active circulating metabolites. Therefore, it may interact differently with cyclosporine. The pharmacokinetics and safety of fluvastatin, 20 mg/day, were evaluated in 20 hypercholesterolemic renal transplant recipients also receiving cyclosporine, usually in combination with azathioprine and methyl prednisolone, during the 14-week study. Fluvastatin area under the curve, maximum plasma concentration, and time to maximize plasma concentration were minimally increased in these patients, unlike findings reported for lovastatin, pravastatin, and simvastatin. This suggests that metabolism of fluvastatin may be less affected by cyclosporine than that of other reductase inhibitors. Fluvastatin was well tolerated, with no evidence of myopathy, rhabdomyolysis, or ophthalmologic abnormalities. These findings and the significant reductions in total cholesterol and low-density lipoprotein cholesterol levels and the ratio of low-density to high-density lipoproteins achieved in these patients support the broader use of fluvastatin to treat hypercholesterolemia in renal transplant recipients.