ddI plus TDF High rate of early virologic failure Rapid selection of resistance mutations Potential for immunologic nonresponse/CD4 cell decline Increased ddI drug exposure and toxicities ZDV/3TC ZDV/3TC is generally not recommended as initial therapy because greater toxicities (including bone marrow suppression; GI toxicities; and mitochondrial toxicities such as lipoatrophy, lactic acidosis, and