Ziagen is a strong drug with lots of potential. It may be useful as one of the two NRTIs in a starting regimen, particularly with Epivir. It may be useful as an addition to a regimen that's already working well, to intensify the anti-HIV effect and decrease viral loads further. And it may be useful as a replacement for a protease inhibitor, the NRTI Zerit, or even a non-nucleoside, once viral load is under control. Preliminary data suggest that these uses offer some benefit, but more and larger studies are needed to better understand when it's most valuable.