My husband has been taking Kaletra (200 mg) and Viramune (200 mg) twice per day since Oct 2002. He has missed only 3 doses this entire time! His viral load has been undetectable and his CD4 count is between 550 and 600. His last lab work indicated that his viral load was suddenly around 3000, and his CD4 count was unchanged. His doctor suspects drug resistance and has ordered a resistance test and is having him do bloodwork over again. Isn't this rather soon for the medications to show resistance in someone with nearly perfect dosage history? This is the only medication he has ever taken since being diagnosed in 2002. Your insights would be greatly appreciated. Thank you.

Congratulations to your husband for this excellent record of adherence! In my experience, it is likely that you are also responsible for this fine record, as spouses, partners, friends and families often provide invaluable assistance to people living with HIV who are trying to take their medications faithfully as prescribed.

First, as your husband's doctor likely told you, it is possible that this represents a transient increase or 'blip' in the CD4 cell count, and that the repeat value will again be below the level of detection. Usually a blip is between 50 and 1,000 copies, and a level of 3,000 would be high for a blip, but it is quite possible. If your husband had a recent viral infection or vaccination before the last value, that also might explain a transient increase.

You ask if 6 years is too soon for resistance to develop. Actually, resistance to some ART regimens, such as those that are based on medications such as NNRTIs like nevirapine (Viramune) and efavirenz, can occur within as short a time as a few days or weeks.

In contrast, regimens containing boosted PIs like Kaletra have a much higher barrier to resistance, and may not be associated with resistance in spite of episodes of viremia over many months and even many years. Indeed, there are several clinical trials that study Kaletra alone, or Kaletra with one or more other drugs followed by Kaletra alone, that have shown that the rate of drug resistance is very low and either unchanged or only marginally increased in those on monotherapy compared to individuals on Kaletra plus one or more other drugs.

The best strategy for now is to wait patiently for the next set of lab tests and the resistance test results, and to fully discuss the results and their implications with his doctor. In the meantime, he should maintain this outstanding record of adherence.