Pharmacokinetics and therapeutic drug monitoring of immunosuppressants.

Immunosuppressive drug treatment has developed considerably in recent years with new methods describing pharmacokinetic-pharmacodynamic relationships. Using in vitro models it is possible to predict the success of clinical immunosuppressive drug combinations. Furthermore, with the advances of analytical methodology it is now possible to measure minute amounts of potent immunosuppressants and to adjust dosing based on concentration measurements. Concentration control, which first was required for cyclosporine A, is being investigated for most immunosuppressive drugs in development. Characterisation of individual drug pharmacokinetics form the basis for successful immunosuppression. Among possible therapeutic drug monitoring methodologies, trough level monitoring is currently the method of choice.