Didanosine plus stavudine with or without hydroxyurea in HIV-1-infected patients: 1 year follow-up

A total of 144 human immunodeficiency vivus (HIV)infected patients (mean CD 4 cell count, 367 cells/mm(3)) were included in a double-blind placebo-cont rolled trial testing the efficacy on surrogate markers of HIV progression o f the combination didanosine (2',3'-dideoxyinosine or DDI) plus stavudine ( 2',3'-didehydro-2',3'-dideoxythymidine or D4T) with or without hydroxyurea. The primary end point was a reduction of HIV RNA levels to below 200 copie s/ml after 12 weeks of treatment. The results showed that the triple combin ation was associated with a move profound decrease in HIV RNA with an incre ased proportion of patients with viraemia <200 copies/ml. This effect persi sted for the majority of the patients after a 48 week follow-up. In contras t. the increase in CD4 cell counts was less in patients treated with hydrox yurea because of lymphopenia, and adverse events were move frequent in hydr oxyurea-treated patients. In conclusion, the addition of hydroxyurea consis tently improved the antiviral activity of the didanosine/stavudine combinat ion over a 48 week follow-up. Increased toxicity and decreased effect on CD 4 cell counts might inspire caution.