Clinical use of rapamycin in renal allograft recipients identifies its relevant toxicity profile and raises unsolved questions: a single-center experience.

Rapamycin is an immunosuppressive drug with a distinct and unique mode of action and a specific side effect profile. We report here briefly on our personal clinical experience using this immunosuppressive drug in different combinations and settings. Rapamycin is without any doubt an efficient drug capable of preventing acute allograft rejection in a variety of immunosuppressive combinations. It is also a very potent drug that is not devoid of serious side effects. Infectious complications as a result of strong inhibition of the immune system are a frequent cause of hospitalization with severe morbidity and even mortality. Fungal infections and pneumonia are among the most devastating complications. As clinical experience with rapamycin grows and the therapeutic window of the drug can be further narrowed, these infectious complications will improve. Wound healing problems and lymphocoeles form another frequent surgical dilemma and are related to the antiproliferative properties of rapamycin. Last, hyperlipidemia warrants the use of statins in the majority of rapamycin-treated patients and whether this unfavorable side effect will offset the theoretically beneficial cardiovascular effects of the drug remains to be determined in controlled trials with long-term follow-up. Finally, the specific antiproliferative properties of rapamycin and the fact that it exerts no nephrotoxicity make this drug an alternative for calcineurin inhibitors and could make it an ideal candidate for treating chronic allograft dysfunction.