Treatment with only protease inhibitors might benefit HIV patients. Laboratory data have shown that the combination of saquinavir with lopinavir and ritonavir may a good regimen. This study will explore this idea.

Treatment with only protease inhibitors might benefit HIV patients, who experience problems with the other antiretrovirals drugs classes. Another reason to only use protease inhibitors is that the remaining classes are spared. This leaves the option to use these classes in the future, for instance in cases of drug resistance. Laboratory data have shown that the combination of saquinavir with lopinavir and ritonavir may a good regimen. This study will explore this idea.

Inclusion Criteria:

1. written informed consent
2. ARV-naïve
3. HIV-1 infected Thai male or female > 18 years old
4. Documented positive test for HIV-1 infection

Exclusion Criteria:

1. Inability to understand the nature and extent of the study and the procedures required.
2. Pregnancy or lactating
3. Active opportunistic infection
4. ALT/ AST more than 2x upper limit
5. creatinine more than 1.5 time the upper limit
6. Smoke cigarettes more than 10 cigarettes a day.
7. Drink alcohol more than 2 units a day
8. Relevant history or current condition, illness that might interfere with drug absorption, distribution, metabolism or excretion.
9. Use of concomitant medication that may interfere with the pharmacokinetics of lopinavir/ritonavir or saquinavir