Are the nucleoside combinations different as backbones?
Studies form the dual therapy era suggested that, at least for the most widely used (and DHHS recommended) regimens of ZDV or d4T plus either ddI or 3TC the answer was no difference. Thus the choice between these backbones would be made on issues such as impact of future treatment options via resistance, frequency and severity of adverse effects, impact on body shape and convenience of administration with the third agent in the regimen. Evidence to clearly inform these debates are limited, but each approach has its pros and cons. Data regarding body shape, for example, vary substantially between studies. In patients who have only received ZDV or d4T backbones, one study (consistent with previous data) found similar rates of fat loss and fat accumulation between these drugs1. Whereas results from a subset of patients drawn from a randomized study of d4T vs. ZDV based regimens (in combination with 3TC + indinavir) in individuals with substantial prior ZDV experience found similar efficac
