Pharmacodynamics of human immunodeficiency virus type 1 protease inhibitors

Many factors are involved in the success or failure of antiretroviral thera py. Recent data suggest that there are significant differences in drug abso rption and disposition for the protease inhibitor class of antiretroviral d rugs, and relationships between plasma concentrations and their antiviral e ffect have been described. Consequently, the issue of whether therapeutic d rug monitoring should be employed for patients receiving treatment with the se drugs has arisen. Several criteria must be met before a drug is consider ed a candidate for therapeutic drug monitoring. These criteria include phar macological, clinical, and analytic components. Although not all the necess ary criteria have yet been met, some of these components have been defined, and additional data are being generated. However, prospectively designed c linical trials must be completed to determine if monitoring protease inhibi tor plasma concentrations provides additional clinical benefit to the patie nt.