Hi Dr. Little. Thanks for taking the time to answer questions.

The virus I contracted is completely resistant to Sustiva, about 50 resistant to protease inhibitors, and some spotty resistance to nucleosides. A regime of Sustiva, Crixivan, 3TC & D4T got me to undetectable, but after a couple of months I had minor blips above 50 and then hit 300 after 18 months. I was very adherent.

After a phenotype on my original blood sample, I dropped Sustiva and added Ritonavir. Now I come in around 50 (70 to <50). Given these results, when is it time to give the protease inhibitors a break? Should I just stay on them until the virus becomes completely resistant to the boost I'm getting from ritonavir?

Thanks! Scott

If you became infected with a virus resistant to sustiva, then I think your best options are the protease inhibitors with nucleosides (such as 3TC and d4T). The best choice of which protease inhibitor(s) and nucleosides should be used would require that I know your exact resistance test results. In general though, for people with multiple protease inhibitor resistance mutations, I tend to favor the use of Kaletra (lopinavir/ritonavir) rather than any single PI. There are other ritonavir/PI combinations which may work as well as Kaletra, but without knowing your test results, I cannot advise. I do think that if you have significant protease inhibitor resistance, you should consider one of these ritonavir-boosted regimens - which means taking a low dose of ritonavir with another protease inhibitor (Kaletra contains this in a coformulation) rather than any single protease inhibitor. I think it is even more important to follow someone with your resistance profile very closely, since you may not have the non-nucleosides (such as sustiva and nevirapine) to fall back on. I would want to see your viral load less than 50!