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A Practical Guide to HAART, PART 1 - HIV and AIDS: The Basics

The Viral Life Cycle

HIV tricks the infected cell into making copies of itself

At this point, if the infected CD4+ cell is activated — which happens any time the immune system is called upon to respond to an infection or allergen or cancerous cell — instead of performing its proper functions, it will start making and releasing new virus. The first step is to make long chains of viral protein. The protease enzyme works like scissors to cut these protein chains into the smaller pieces that make up HIV. The newly cut pieces are assembled into new virus particles, which then “bud” out from the host cell and can go on to infect other cells.

Protease inhibitors (PIs) are drugs that interfere with the action of protease. They prevent the protease enzyme from cutting the long chains of new viral protein. Although new virus can be formed, it is defective and cannot infect new cells. Protease inhibitors have a very powerful ability to suppress the virus and are an important part of many drug combinations.

Currently approved protease inhibitors are:

    • amprenavir (Agenerase)
    • indinavir (Crixivan)
    • lopinavir and ritonavir (Kaletra)
    • nelfinavir (Viracept)
    • ritonavir (Norvir)
    • saquinavir (Invirase)
    • tipranavir (Aptivus)
    • fosamprenavir (Telzir)
    • atazanavir (Reyataz)
Sometimes your doctor may prescribe two PIs together. This is because one PI, usually ritonavir, can “boost” the level of the other PI. Examples of dual-PI or PI-boosted regimens include the following:
    • ritonavir/amprenavir
    • ritonavir/indinavir
    • ritonavir/saquinavir
    • ritonavir/atazanavir
    • ritonavir/tipranavir
Many other PIs are being studied.

Another group of drugs that is being studied is called immune boosters. These can help raise the level of CD4+ and other cells. An example of an immune booster is IL-2 (interleukin-2). You may also hear about “therapeutic vaccines.” These are meant to be used in HIV positive people to help improve their immune system’s ability to fight HIV. Many of these products are being tested in clinical trials.
 

Revised 2006


 

Decisions about particular medical treatments should always be made in consultation with a qualified medical practitioner who is knowledgeable about HIV-related illness and the treatments in question. MORE