Interaction Between Rimonabant and Cyclosporine and Tacrolimus

Renal transplant recipients are treated with life-long immunosuppressive therapy in order to prevent acute rejection episodes. The calcineurin inhibitors (CsA and Tac) are the back-bones in the immunosuppressive treatment and they have a very narrow therapeutic index. It is therefore essential to assure that new drug to be used in transplanted patients do not interact with CsA and Tac. Even though rimonabant is metabolized via the same enzyme as CsA and Tac (CYP3A4) previous in vitro and in vivo studies with relevant probe drugs in healthy volunteers do not indicate the presence of any relevant pharmacokinetic interaction. However, to be absolutely sure that it is safe to administer rimonabant in transplanted patients a 12-hour pharmacokinetic interaction investigation is included for 16 patients in the present pilot study (8 patients on CsA and 8 patients on Tac).