SAQUINAVIR (SQV)-BASED THERAPY WITHIN A DIRECTLY OBSERVED THERAPY (MAT/DOT) FOR THE MANAGEMENT OF HIV-INFECTED INTRAVENOUS DRUG USERS (IDUs) IN A METHADONE (MET) PROGRAM

Jennie Prasad¹, Stanley de Vlaming^2,3, Michelle Jones¹, Annabel Mead^2,3, Nadine Smith³, Brian Conway^1,2,3
1Department of Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia; ²Pender Community Health Centre, Vancouver, British Columbia; ³Vancouver Coastal Health Authority, Vancouver, British Columbia

Objectives: Treatment of HIV-infected IDUs has been made easier by the development of directly observed therapy (MAT/DOT) programs and the use of ritonavir (RTV) to allow the administration of protease-inhibitor (PI) based regimens once daily. We have evaluated the virologic and immunologic response to therapy in IDUs receiving HAART with nucleoside analogues (NRTIs) with RTV/SQV.
Methods: These regimens were administered to 14 individuals. All medication was administered under direct observation along with MET, with the second dose, if applicable, taken at home (adherence verified the next morning). Follow-up (including an ongoing assessment of recreational drug use) occurred at months 1, 3, then every 3 months, or more frequently if clinically indicated. Pharmacokinetic studies were done in selected individuals.
Results: Within the study population, 11 individuals received SQV 1600 mg with RTV 200 mg qd, while 3 received SQV 800 mg with RTV 100 mg bid. At baseline, the mean CD4 count was 141 [9-340] cells/mm³, and the mean plasma viral load 268,921 [10,100 –840,000] copies/mL. In follow-up (mean 15 months) the mean CD4 count had risen to 333 cell/mm³, with 9/14 (64%) achieving maximal virologic suppression. SQV pharmacokinetics studies are underway to determine the association between drug exposure and virologic suppression. Further, resistance studies are being performed in cases with ongoing viral replication.
Conclusions: Directly observed therapy can be successfully undertaken in IDUs receiving MET, using once daily RTV/SQV-based regimens. Despite the pill burden this represents, this may offer a useful alternative for such patients for whom HAART is indicated and who are unwilling or unable to take NNRTI-based regimens.