EVALUATION OF PATIENTS RECEIVING LONG-TERM TWO-DRUG ANTIRETROVIRAL THERAPY (ART)

Kevin Levitt, Sharmistha Das, Brian Conway
Department of Pharmacology & Therapeutics, University of British Columbia, Vancouver, British Columbia

Objectives: The current standard of care for the initiation of ART calls for the use of three drug combinations (highly active ART or “HAART”). However, until 1996, one and two drug regimens were commonly used. We identified individuals who remain on “pre-HAART” regimens in clinic, with a view to making specific recommendations regarding their ongoing management.
Methods: This retrospective chart review included all individuals actively followed in our center (³4 visits/year) who were on double drug therapy, or had never received ART. They were evaluated based on virologic and immunologic parameters, viral resistance, and metabolic changes over time.
Results: In reviewing 270 records, there were 13 (4.8%) patients still receiving double combination therapy, usually d4T/3TC (n=8), and 9 (2.7%) who had never been treated. Data are summarized below:

Only 4/13 treated patients qualify for the initiation of ART according to current standards (CD4 count<350 cells/mm³), and only 7/13 maintained V_L<50 copies/mL. Drug resistance (4/4 M184V, 2/4 K70R) developed in 4/6 who were not suppressed. One individual on d4T/3TC developed TGs=8.3 mmol/L. No other metabolic abnormalities were detected.
Conclusions: Double combination therapy, initiated according to contemporary guidelines and continued up to the present time, maintains virologic suppression in only 50% of cases. Where this is not the case, drug resistance is commonly present, limiting future therapeutic options. Consideration should be given to stopping or intensifying the regimen of patients who remain on two drug therapy, perhaps within the context of a clinical trial.