The process of using in vitro models to predict in vivo drug interactions is still in itsinfancy, and extensive validation of this approach is needed.
In vitro models predictiveof in vivo drug interactions will be essential for rapid, costeffective screening of phar-maceutical compounds and are important for reducing risks to patient safety.
Currently,these models are constructed from a combination of laboratory and theoretical components.
Ideally, in a valid model,
the in vivo decrease in clearance caused by coadministration of an inhibitor would be specifically predicted by the decrease in reactionvelocity for the same compound in vitro when theinhibitor is present in the same concentration.