Abstract
The identification of relationships between plasma concentrations of protease inhibitors and later, the non-nucleoside reverse transcriptase inhibitors and their efficacy and toxicity has caused a growing interest in the concept of therapeutic drug monitoring in the treatment of HIV infection. Some evidence suggests a beneficial effect of therapeutic drug monitoring of protease inhibitors. More recently, plasma protease inhibitor concentrations have been combined with viral susceptibility into one parameter, the inhibitory quotient, which may be a better predictor of the response to therapy, especially in pretreated patients. This paper reviews the current literature on therapeutic drug monitoring and the inhibitory quotient in the management of HIV infection and speculates on the future role of pharmacogenomics in this therapeutic area.