title: A randomized controlled trial of verapamil on cyclosporine nephrotoxicity in heart and lung transplant recipients.
abstract: BACKGROUND
  Cyclosporine (CsA) is a potent immunosuppressive drug widely used in organ transplantation and in the treatment of autoimmune diseases (1, 2). However, its common nephrotoxic effect is a major limiting factor. Short-term CsA treatment has been shown to cause reversible renal vasoconstriction, whereas long-term treatment can lead to an afferent arteriolopathy and chronic renal failure.
  
  
  METHODS
  We performed a randomized controlled trial to examine the short-term renal effects of verapamil in 32 CsA-treated heart or lung transplant recipients. Sixteen patients each were randomized to receive a 6-week course of verapamil or control treatment (atenolol in hypertensive patients and placebo in normotensive patients) 1-2 months after transplantation. An 8-hr sequential clearance study of inulin and p-aminohippuric acid for estimating glomerular filtration rate and renal plasma flow, respectively, was performed at baseline and at completion of study. The integral area under the curve of the clearance parameter over 8 hr was then calculated to generate a clearance-time index.
  
  
  RESULTS
  There was no difference in the clearance-time indices for inulin and p-aminohippuric acid between the two groups at baseline. However, at the completion of study, the within-group change in the glomerular filtration rate clearance-time index was different between the verapamil and control groups (48+/-20 vs. -35+/-17 ml/min/1.73 m2 x hr, respectively; P=0.0038). A similar trend was seen for renal plasma flow, but did not reach statistical significance. Mean arterial blood pressure and whole-blood CsA levels did not differ between the two groups during the study. Verapamil treatment was also associated with a decrease in CsA dose requirement (7.6+/-0.58 mg/kg/day at baseline vs. 4.6+/-0.40 mg/kg/day at completion; P<0.001) without any significant change in trough whole blood CsA levels. Rejection episodes did not differ between the two groups.
  
  
  CONCLUSIONS
  The use of verapamil in the heart or lung transplant recipients may therefore provide both renal protective effects and cost savings.
authors.affiliation: Department of Medicine, Toronto Hospital and University of Toronto, Ontario, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Chan
authors.forename: J
authors.initials: J
authors.lastname: Maurer
authors.forename: C
authors.initials: C
authors.lastname: Cardella
authors.forename: D
authors.initials: D
authors.lastname: Cattran
authors.forename: Y
authors.initials: Y
authors.lastname: Pei
mesh_terms: D000328:Adult; D003365:Costs and Cost Analysis; D016572:Cyclosporine / Q000009:adverse effects*; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D016041:Heart-Lung Transplantation / Q000502:physiology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects*; D007674:Kidney Diseases / Q000139:chemically induced / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D014700:Verapamil / Q000494:pharmacology*
chemical_list: D007166:Immunosuppressive Agents; D016572:Cyclosporine; D014700:Verapamil