Effects of voriconazole on tacrolimus metabolism in a kidney transplant recipient.

Infection occurs frequently in the organ transplant recipients during the post-transplant period because of immunosuppression. Therefore, prophylactic antimicrobial agents are often used. The azole antifungals, widely prescribed prophylactically, are known to have many drug-drug interactions. This report presents a case of drug-drug interaction between voriconazole and tacrolimus in a kidney transplant recipient. Voriconazole treatment led to a dramatic increase in tacrolimus concentration that required its discontinuation in spite of the manufacturer's guidelines that recommend a reduction of tacrolimus dosage by one-third. The present drug-drug interaction can be attributed to a strong inhibitory effect on cytochrome P450-3A4 activity by voriconazole. When voriconazole and tacrolimus are coadministered, close monitoring of tacrolimus blood levels is recommended as the rule-of-thumb reduction of tacrolimus dose by one-third may not be satisfactory.

Older kidneys donor transplantation: five years' experience without biopsy and using clinical laboratory and macroscopic anatomy evaluation.

INTRODUCTION: The exponential increase in organ demand is not associated with a similar increase of available kidneys. This emergency led to expanded criteria to consider a kidney transplantable. The aim of this retrospective study was to explain our use of older donor kidneys without biopsy. MATERIALS AND METHODS: Between 2000 and 2005, 58 older kidneys were harvested: 27 were transplanted in our center; 13 were discarded; and 18 were transplanted in other centers. We considered 3 factors to define kidney quality: macroscopic anatomy, multiple factors linked to the donor, and clinical-laboratory data. After transplantation, we observed the patients for at least 1 year and up to 6 years. DISCUSSION: At 1 year, 24/27 (89%) patients had a functional kidney, 2 patients showed an initial renal failure and 1 patient lost the kidney. At maximum follow-up, 19 patients (70%) had functional kidneys, 4 with initial renal failure. These results compared with the kidneys harvested using Standard Donor Kidney Criteria are acceptable. Obviously we need long-term follow-up to increase, the amount of data and obtain a definitive outcome. CONCLUSION: Biopsy is the gold standard for the definition of an older kidney's quality. When a biopsy is not feasible, the study of the macroscopic anatomy the kidney's donor and of some donor's parameters represent an acceptable biopsy alternative, being able to rescue some organs that would be otherwise lost.