Treatment Literacy/Information needs/ARV

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Antitretroviral drugs:

Preknowledge:

HIV 101

What Is Antiretroviral Therapy (ART)?

ARV therapy means treating viral infections like HIV with drugs. The drugs do not kill the virus. However, they slow down the growth of the virus. When the virus is slowed down, so is HIV disease. Antiretroviral drugs are referred to as ARV. ARV therapy is referred to as ART.

Goal of ART:

HIV has a complex life cycle that involves several steps. Disease progression occurs when the virus replicates (reproduces) and infects new cells. The key goal of antiretroviral therapy is to slow - or ideally stop - HIV replication and enable recovery of the immune system. Antiretroviral drugs, which target different steps of the viral life-cycle, are the mainstay of anti-HIV treatment.

HIV medications types or "classes":

• NRTIs (nucleoside or nucleotide reverse transcriptase inhibitors)
• NNRTIs (non-nucleoside reverse transcriptase inhibitors)
• PIs (protease inhibitors)
• Entry inhibitors
• Integrase inhibitors

All five classes of medications have been designed to interfere with HIV's ability to copy itself -- that is, to reproduce inside the body. Each class of medication stops the virus at a different moment in its reproductive cycle.

Example

Think of HIV as a breeding factory set up inside a T cell. All it wants to do is grow inside of you and make duplicates of itself. NRTIs act like broken building blocks so that the factory HIV tries to build in your T cells is made with broken bricks. NNRTIs act like bad supervisors who give the wrong instructions to HIV during the building process. Protease inhibitors act like workers who put defective parts in each new virus being built on the factory's assembly line. Fusion inhibitors act like locks on the factory door that prevent HIV from getting inside. Analogy courtesy of the British Columbia Persons With AIDS Society.

How are ARVs effective?

There are now many HIV medications. However, none of these medications can cure HIV, and no single drug taken alone is effective. But when several medications (usually three) are taken in combination, they can control the quantity of virus in the body and maintain the health of the immune system. Effective therapy has been shown to reduce the number of new cells infected by HIV and to impede the ability of the virus to evolve drug-resistant.

Drug regimens:

• Single drug regimens (monotherapy) : Monotherapy should not be used in the treatment of HIV infection, however, it continues to play a very important role in the prevention of mother to child transmission (MTCT).
• Dual drug regimens: Dual therapy is moderately effective, but is unlikely to produce long term durable benefit in most patients. It is not the standard of care, but is considerably better than no therapy and should be considered in patients unable to afford HAART (see below). This should only be applied to patients who have already developed AIDS. In this setting, dual therapy is better than no therapy otherwise resistance is a major concern if dual nucleoside therapy is prescribed to asymptomatic patients. The efficacy of two drug combinations (dual therapy is greater than monotherapy potentially achieving a 1.5 – 1.8 log reduction in viral load).Triple combinations are the standard of care.
• Triple combinations also known as highly active antiretroviral therapy (HAART): The combination of three synergistic antiretroviral agents remains the standard of care; substantial reductions in medication prices continue to make triple-drug regimens more affordable.

Web Resources

For more information on HIV medication see: A to Z of drugs HIV medication basics HIV treatment during pregnancy Pregnancy and HIV/AIDS: A Practical Guide (RTF format -- typesetting incomplete) HIV treatment in children Antiretroviral therapy in children WHO’s Antiretroviral therapy in adults & adolescents HIV and Injecting drug users (IDUs) Drug resistance

Monitoring the immune system:

A viral load test and CD4 cell count together can evaluate current immune system status, guide and monitor treatment decisions and predict rate of disease progression in both the short- and the long-term.

Web Resources

For more information on HIV Monitoring Tests see: Monitoring Test Basics Monitoring the immune system WHO consultation on technical and operational recommendations for scale up of laboratory services and monitoring HIV antiretroviral therapy in resource-limited settings

See also:

Web Resources

Treatment Updates