**Metabolic Drug Interactions with Immunosuppressants Metabolic Drug Interactions with Immunosuppressants**

DOI: 10.5772/intechopen.74524

Katalin Monostory Katalin Monostory

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.74524

#### **Abstract**

Organ transplantation has become a routine clinical practice for patients with endstage disease of liver, kidney, heart, or lung. Although improved immunosuppressant therapy substantially contributes to the success of transplantation, clinicians continue to face challenges because of wide interindividual variations in blood concentrations resulting in subtherapeutic or supratherapeutic levels. Many undesired side-effects or therapeutic failure of immunosuppressants as a consequence are the results of differences or changes in drug metabolism. Considering genetic and nongenetic factors, such as co-medication, can refine the immunosuppressant therapy, facilitating personalized treatments to individual recipients. This review provides an up-to-date summary of functional polymorphisms of enzymes involved in the metabolism of immunosuppressants with low molecular weight and of the clinical significance of metabolic drug interactions between immunosuppressive agents and other drugs in therapeutic regimens of transplant recipients.

**Keywords:** drug metabolism, genetic polymorphism, phenoconversion, calcineurin inhibitors, mTOR inhibitors, corticosteroids, inosine monophosphate dehydrogenase inhibitors
