4th International Workshop on Adverse Drug Reactions and Lipodystrophy in HIV 22-25 September 2002, San Diego, CA, USA

DIFFERENT IMPACT ON METABOLIC PARAMETERS OF AMPRENAVIR/RITONAVIR REGIMENS WITH TENOFOVIR VERSUS EFAVIRENZ

Antiviral Therapy 2002; 7:L31 (abstract 45)

M Thompson¹, K Tashima², R Schooley³, R Haubrich⁴, L Yau⁵, S Hessenthaler⁵, J Hernandez⁵ and K Pappa^5
1AIDS Research Consortium of Atlanta, Atlanta, Ga., USA; ²The Miriam Hospital, Brown University,USA; ⁵GlaxoSmithKline, Research Triangle Park, NC, USA

BACKGROUND: The use of low-dose ritonavir as a pharmacokinetic booster for protease inhibitors is currently standard practice. The metabolic impact that ritonavir may impose is not yet fully understood. Furthermore, other components of the regimen may also have an effect on lipid parameters.

METHODS: One hundred and fifteen antiretroviral therapy (ART)-experienced subjects were treated with amprenavir (600 or 900 mg twice daily)/ritonavir 100 mg twice daily/abacavir 300 mg twice daily/another nucleoside reverse transcriptase inhibitor (NRTI)/and either daily efavirenz 600mg or tenofovir 300 mg. Adult subjects with HIV-1 RNA ≥1000 copies/ml, CD4 counts ≥50 cells/mm³ and phenotypic susceptibility to amprenavir, abacavir and another NRTI of choice were eligible. Subjects were stratified by prior protease inhibitor (PI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) experience and randomized to the amprenavir doses. NNRTI-naïve subjects received efavirenz, while NNRTI-experienced subjects received tenofovir.

RESULTS: At week 24, laboratory data were available for 91 subjects. Median change from baseline (BL) data are presented by group (in order): 600 amprenavir + tenofovir (n=32), 900 amprenavir + tenofovir (n=28), 600 amprenavir + efavirenz (n=18), 900 amprenavir + efavirenz (n=13). Median changes in total cholesterol by group were 0.50 mg/dl, 8.50, 57.00* and 73.00*. HDL median changes were 1.00 mg/dl, -1.00, 0.00 and 6.00; LDL median changes were 12.4 mg/dl, -5.80, 44.20 and 14.80. Triglyceride median changes were 41.0* mg/dl, 35.0, 105.0* and 105.0* (*denotes P<0.05 comparing the change from baseline value within each treatment group). The regimens were well tolerated; a total of six SAEs (2/6 while subjects were in screening) and six abacavir hypersensitivity reactions were reported up to week 24.

CONCLUSION: The amprenavir regimens described above in combination with low dose ritonavir were well tolerated. Lipid profiles were comparable in patients randomized to the amprenavir 600 mg and amprenavir 900 mg treatment arms. Subjects who received efavirenz with either dose of amprenavir had significant increases from baseline in their total cholesterol and fasting triglyceride levels by 24 weeks. The increase in triglycerides was greater in the efavirenz treatment groups than in the tenofovir treatment groups.

Presenting author: M Thompson

2002-09-22
45

Copyright © 2002 - International Medical Press Ltd.. Reproduction of this abstract (other than one copy for personal reference) must be cleared through the Medical Editor, International Medical Press, 36 St Mary-at-Hill, London EC3R 8DU, United Kingdom.