Diurnal variation of plasma protease inhibitor concentrations

Diurnal variation in plasma concentrations of nelfinavir and ritonavir has previously been described. Plasma concentrations of 29 pharmacokinetic profiles with indinavir, amprenavir and saquinavir were evaluated, and a statistically significant median difference of 57.6% was found between morning and evening, with the morning C-through being higher than the evening C-through.Consequently, a change in dosing intervals might result in more balanced plasma protease inhibitor concentrations, thereby decreasing toxicity and the risk of virological failure.