adult dose of 3 capsules (lopinavir 400 mg/ritonavir 100 mg) twice daily resulted in plasma concentrations approximately 50% of those seen in nonpregnant adults.4 An increased dose Ritonavir Pharmacokinetics Absorption Bioavailability. Well absorbed from GI tract; peak plasma concentrations attained within 2–4 hours (fasting). 1 2 3 75 209 Erratum in Clin Pharmacokinet 1998 Dec;35(6):473. Ritonavir is 1 of the 4 potent synthetic HIV protease inhibitors, approved by the US Food and Drug Administration (FDA) between 1995 and 1997, that have revolutionised HIV therapy. The extent of oral absorption is high and is not affected by food This study will focus on the combination of Saquinavir (SQV) and RTV. Firstly, this is because SQV is widely used in Thailand and has shown to be an adequate first and second line antiretroviral agent. The multiple-dose pharmacokinetics of ritonavir were investigated in four groups of human immunodeficiency virus-positive male subjects (with 16 subjects per group) under nonfasting conditions; a 3:1 ritonavir:placebo ratio was used. Ritonavir was originally developed as an inhibitor of HIV protease. It is one of the most complex inhibitors. It is now rarely used for its own antiviral activity, but remains widely used as a booster of other protease inhibitors. Letter to the Editor Nephron 2001;87:186–187 Pharmacokinetics of Ritonavir and Saquinavir in a Haemodialysis Patient Hassane Izzedine a Vincent Launay-Vacher a Mayeule Legrand b Guy Aymard b Gilbert Deray a Departments of a Nephrology and b Pharmacology, Pitié-Salpêtrière Hospital. A study of ritonavir pharmacokinetics in healthy males and females showed no statistically significant differences in the pharmacokinetics of ritonavir. Pharmacokinetic differences due to race have not been identified. Academia.edu is a platform for academics to share research papers.