文档介绍：VIREAD (Tenofovir DF) UpdateViread Update?ics?Safety & Tolerability?Efficacy?icsTenofovir DF Pharmacology?Once-daily dosing–Long intracellular half-life (tenofovir-DP)?Activated cells: 10 hours; Resting cells: 50 hours–Serum t1/2?17 hours?Renally cleared–interval adjustment for CrCl < 50 mL/min?Bioavailability –Can be given without regard to food** US package insert August 2003Tenofovir DF Pharmacology (cont’d)?Not a substrate or inhibitor of human CYP450 enzymes?No significant plasma drug interactions with:–FTC–3TC–ABC–EFV–LPV/r–IDV–FOS-APV–TPV?Clinically significant drug interactions with:–ddI (plasma levels increased ?44-60%)–ATV (AUC ? 25%)Background:?Previous PK studies with ddI EC 400 mg have demonstrated increased ddI exposures when co-administered with TDF1Objectives:To evaluate PK of ddI EC 250mg dosed: ?Separated dosing –on an empty stomach two hours prior to TDF and a light meal?In a simplified dosing regimen–together with TDF and a light meal –together with TDF on an empty stomach1 Viread Prescribing InformationKearney B, et al. 10th Conference on Retroviruses and Opportunistic Infection, Feb. 2003, Abstract 533Study 984Tenofovir DF and Didanosine EC Interaction: Background & ObjectivesRegimenddI AUC(?g?hr/mL)ddI Cmax(?g/mL)ddI EC 400 mg EC 250 mg + TDF- separated by 2 hours (per current regulatory labeling) (0%) (? 11%)- together with a light meal (simplified dosing) (? 11%) (? 29%)- together on an empty stomach (simplified dosing) (? 14%) (? 8%)Kearney B, et al. 10th Conference on Retroviruses and Opportunistic Infection, Feb. 2003, Abstract 533Viread Prescribing InformationStudy 984Tenofovir DF and Didanosine EC Interaction: Results?ddI EC 250 mg dosed with TDF, in the presence or absence of food, results in drug exposures similar to ddI EC 400 mg dosed alone?When TDF and ddI is given, dose of ddI should be decreased to 250 mg in patients ?60 kg*Kearney B, et al. 10th Conference on Retr