Pharmacokinetics of saquinavir hard gel/ritonavir (1000/100 mg twice daily) when administered with tenofovir diproxil fumarate in HIV-1-infected subjects.
OBJECTIVE
To investigate whether the administration of tenofovir diproxil fumarate 300 mg once daily alters the plasma pharmacokinetics of the saquinavir hard gel/ritonavir combination in HIV-1 infected individuals.


METHODS
On day 1, 12 h pharmacokinetic profiles for saquinavir/ritonavir (1000/100 mg given twice daily) were obtained for 18 subjects. All subjects were receiving ongoing treatment with a saquinavir/ritonavir-containing regimen. Tenofovir diproxil fumarate 300 mg given once daily was then added to the regimen and blood sampling was repeated at days 3 and 14. Saquinavir and ritonavir concentrations were measured by HPLC-MS/MS, and tenofovir concentrations by HPLC with UV detection.


RESULTS
Following the addition of tenofovir diproxil fumarate to the regimen, saquinavir and ritonavir plasma concentrations were not significantly different compared with day 1. Thus the geometric mean ratios (95% confidence intervals) for the area under the concentration-time curve were 1.16 (0.97, 1.59) and 0.99 (0.87, 1.30) for saquinavir and 1.05 (0.92, 1.28) and 1.08 (0.97, 1.30) for ritonavir, on days 3 and 14, respectively.


CONCLUSIONS
Tenofovir diproxil fumarate did not alter the pharmacokinetics of saquinavir hard gel/ritonavir.
Boffito
Marta
M
PK Research Ltd., St. Stephen's Centre, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH, UK. marta.boffito@chelwest.nhs.uk
Back
David
D
Stainsby-Tron
Meredith
M
Hill
Andrew
A
Di Perri
Giovanni
G
Moyle
Graeme
G
Nelson
Mark
M
Tomkins
Jaqui
J
Gazzard
Brian
B
Pozniak
Anton
A
D000225:Adenine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000494:pharmacology*; D019540:Area Under Curve; D004338:Drug Combinations; D004347:Drug Interactions; D005782:Gels; D015658:HIV Infections / Q000188:drug therapy*; D017320:HIV Protease Inhibitors / Q000008:administration & dosage / Q000493:pharmacokinetics*; D015497:HIV-1; D006207:Half-Life; D006801:Humans; D008875:Middle Aged; D063065:Organophosphonates / Q000008:administration & dosage / Q000494:pharmacology*; D019438:Ritonavir / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019258:Saquinavir / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000068698:Tenofovir
D019380:Anti-HIV Agents; D004338:Drug Combinations; D005782:Gels; D017320:HIV Protease Inhibitors; D063065:Organophosphonates; D000068698:Tenofovir; D000225:Adenine; D019258:Saquinavir; D019438:Ritonavir