Dear Dr. Henry, I read a recent answer from you in which you stated that you would suggest Kaletra for the person until the VL goes down and then switch to Viramune or atazanavir (sp?). I am resistant to Viramune/Sustiva and will be switching to Kaletra. Why do you advise the switch from Kaletra? Are the side effects that bad? Thank you very much for your assistance. DJ

Kaletra is an excellent drug due to its pharmacokinetic properties creating a high barrier to PI resistance. For persons without resistance who are fully suppressed, that high barrier to resistance is no longer as crucial as simplicity, tolerability, and preservation of future options in my opinion. For persons with resistant virus the situation is quite different and the barrier to resistance is crucial. For persons with NNRTI and usually some NRTI resistance I have good long-term results with regimens utilizing boosted PIs such as Kaletra and genotype/experience choosed background regimens. I have many patients who tolerate Kaletra well long-term. KH