Therapeutic drug monitoring: ready For clinical practice?

Stephen Becker, MD, argues that further study is needed before the routine application of TDM can be recommended.
Medscape HIV/AIDS 7(2), 2001

Therapeutic drug monitoring (TDM) has much theoretic appeal in HIV disease management. The HIV protease inhibitors (PI) in particular have been considered logical candidates for TDM primarily because virologic outcomes have been correlated with trough levels of the PI. In addition many pharmacologic and host factors have been felt to influence PI exposures, including variability in absorption, protein binding, P450 metabolism, and cellular efflux pumps (specifically P-glycoprotein). For these reasons, TDM has been proposed as a means to ensure adequate drug exposure for the PIs, and perhaps as a means of correlating drug toxicities with plasma concentrations.