Lopinavir used to be called ABT-378. It is manufactured by Abbott Laboratories. Lopinavir is a protease inhibitor. The amount of Lopinavir in the blood stream stays much higher if it is taken with a small amount of ritonavir, another protease inhibitor. Kaletra is a combination of lopinavir and ritonavir in the same capsule.
Protease inhibitors prevent the protease enzyme from working.
HIV protease acts like a chemical scissors. It cuts the raw material for HIV into specific pieces needed to build a new virus. Kaletra is an antiviral drug for adults with HIV infection. There are no absolute rules about when to start antiviral drugs. Others want to save the strongest drugs until they are needed, later in the course of HIV disease.