The rapid emergence of resistant HIV strains has been observed in patients receiving monotherapy with a nucleoside analog or non-nucleoside reverse transcriptase inhibitor. Use of combination therapy with two nucleoside drugs or convergent combination therapy with two nucleosides and a non-nucleoside RT inhibitor may minimize the evolution of these resistant HIV strains. Since toxicity is a major problem in patients with advanced disease who are receiving combination nucleoside therapy, alternating the two drugs may provide a way of retaining several benefits of combination therapy while minimizing the increased toxicity.