In this episode, we review clinical pearls and common pitfalls of immunosuppression regimens for organ transplantation with a particular focus on tacrolimus and mycophenolate. Key Concepts Most recipients of an organ transplantation will be on a two or three drug regimen. The most common regimen is tacrolimus and mycophenolate with/without a corticosteroid. Tacrolimus is hepatically eliminated and susceptible to CYP3A4 and PGP drug interactions. Particularly at higher drug concentrations, it is associated with nephrotoxicity and neurotoxicity (among several other adverse effects). Mycophenolate is unstable in the acidic environment of the stomach. The two formulations on the market are CellCept (which uses a prodrug, mycophenolate mofetil, that is converted in the liver to an active compound) and Myfortic (an enteric-coated formulation of mycophenolic acid, which releases after exiting the stomach). The intensity of an immunosuppression regimen is determined by numerous factors, including the type of organ, how long ago the organ was transplanted, if acute rejection has occurred in the past, patient-specific risk factors, and more. Additional Resources Register to be a donor at Donate Life America (https://donatelife.net) or at the HRSA OrganDonor.gov site (https://www.organdonor.gov) Learn more about stem cell donation and transplant at https://bethematch.org