additional effect of Nevirapine?

Question:

I have had Toxoplasmosis and CMV-Gastritis, both cured, and my viral load dropped from 1.000.000 to undetectable under combination therapy since 15 month, at present Ritonavir 2 x 600, Saquinavir 2 x 400, DDI 2 x 300 and d4T 2x 40. CD4 are around 550, all other lymphocytes also completely normal. Now we have done a Viral load (RocheKit) after Ultrazentrifuation and have found 600 copies in the sixfold concentrated plasma, that means there are still around 100 copies in the blood. Hoping to get completely cured one good day, I think now to add Nevirapine to the present combination as a fifth component and would like to ask You, if this is a good choice?

Dr. Pavia's Response:

Long answer: Nevarapine is well tolerated, potent, and unlikely to lead to nevarapine resistant virus if you have low viral replication. There is a drug drug interaction between nevarapine and both saquinavir and ritonavir which leads to lower drug levels for the protease (about 27% decrease for Saquinavir and 11% decrease for ritonavir in AUC). These are probably not large enough to matter.

A few cautions though. We really don't know if it is necessary, possible or desirable to suppress you to < 100 or < 20 to get very long lasting suppression of virus that will not allow resistance. Although we all hope that Alan Perelson and David Ho are right about eradicating virus, remember that they are cautiously trying this in people who are new seroconverters. If you have been infected a long time and have taken a lot of other drugs already, you may be trying for the longest suppression possible rather than eradication, and it may be more important to use the right number of drugs (to minimize pills, costs, side effects and to preserve another set of options)

Good luck with a tough decision

Andrew T. Pavia, MD