Target concentration strategy for cyclosporin monitoring.

The target concentration concept has been proposed as a potential alternative to the established, and probably much abused, therapeutic range method of interpreting concentrations of therapeutic drugs in plasma, serum or blood when individualising drug dosages. This paper raises for debate the possibility of extending this alternative concept to immunosuppressant monitoring with cyclosporin, where there has been considerable difficulty in establishing therapeutic ranges which are widely accepted and applied. In its broader application, the target concentration strategy does present advantage to the clinician in precision, ability to calculate the dose directly from the target concentration and clearance, as well as a clearer concept of an optimal concentration (differentiating desired and adverse effects).