Tacrolimus

Background

• Drug used in solid organ transplantation that has a narrow therapeutic window

Safety

Adverse Drug Reactions

• Nephrotoxic and neurotoxic, with risk that is proportion to serum levels

Drug-Drug Interactions

• It is a substrate for CYP 3A4
  • Erythromycin, clarithromycin, clotrimazole, fluconazole, and ketoconazole can increase tacrolimus levels
    • Interaction with macrolides is lowest with azithromycin, which should be preferred
  • Rifampin can decrease tacrolimus levels and precipitate acute rejection
• Other interactions include
  • Quinupristin-dalfopristin and chloramphenicol can increase tacrolimus levels
  • Sulfonamides and vancomycin can increase risk of nephrotoxicity, so creatinine should be monitored closely