Pharmacogenomics of Immunosuppressants

Long-term survival of patients after solid organ transplantation mainly depends on the rational use of immunosuppressants, including the calcineurin inhibitors (e.g., cyclosporine A and tacrolimus) and antimetabolic drugs (e.g., mycophenolic acid). These drugs are characterized by narrow therapeutic index, large interindividual and individual variabilities in pharmacokinetics and pharmacodynamics, promoting an urgent for therapeutic drug monitoring and individualized therapy. The pharmacokinetic variabilities can be partly explained by the genetic polymorphisms of the transporter and metabolic enzyme genes, such as cytochrome P450 (CYP) 3A4/5 polymorphisms for calcineurin inhibitors and UDP glucuronosyltransferase (UGT) 1A9 genetic polymorphisms for mycophenolic acid. In recent years, genetic polymorphisms in pharmacodynamics of immunosuppressants have been paid increasing attention. Monitoring of these pharmacogenetic biomarkers provides us a powerful approach to develop individualized dosage regimen for the immunosuppressants.