Figure 3. Ritonavir Boosting of Amprenavir

This figure illustrates the concept of pharmacokinetic enhancement as shown by low dose ritonavir boosting of amprenavir. Plasma amprenavir levels achieved with full dose amprenavir (1200 mg bid) taken without ritonavir are shown by the blue line. Plasma amprenavir levels generated by a reduced dose of amprenavir (600 mg bid) combined with low dose ritonavir (100 mg bid) are shown by the yellow line. Note the ritonavir-amprenavir combination generates lower peak (Cmax) levels but higher trough levels (Cmin) when compared with amprenavir alone. Similar pharmacokinetic enhancement occurs when combining ritonavir with other protease inhibitors. This figure is not intended to represent exact amprenavir serum levels, but rather to show approximate relative changes in serum amprenavir levels achieved with ritionavir pharmacokinetic enhancement.

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