Hi,

I'm using a Sustiva + Combivir combo fairly well for 4 1/2 yrs with viral load undetectable at all times and 100% adherence. I have been on other combinations in the past but never experienced virologic failure. I have had hepatitis A and lipoatrophy. I have never been on PI. In case viral rebound occurs with drug resistance, how could I know if it's due to the NNRTI or accumulated AZT mutations (TAMs) or to Epivir (3TC). How does it usually happen? Do these situations show different patterns of blips/big rises? If so which would the best PI based combo to switch to?

It sounds like you are doing great on your current regimen with the potential exception of lipoatrophy which may be associated with the NRTIs. I suspect viral rebound will not occur if you continue to take your medication consistently. However, if it did resistance is likely to be to the NNRTI, 3TC or both. Only after months of viremia does resistance to AZT develop. If viral rebound is confirmed you can do genotypic resistance testing to determine if there is any resistance and if so whether it is to the NNRTI, 3TC or both. After this you can determine what other options exist for your next regimen. Obviously you would need to talk to your provider about what to do next, but if treatment failure is identified early you will have many options to consider, including multiple very active protease inhibitors.

Best, Eric