Human Immunodeficiency Virus (HIV) (cont.)
Mary D. Nettleman, MD, MS, MACP
Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.
Charles Patrick Davis, MD, PhD
Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
In this Article
- Human immunodeficiency virus (HIV) facts
- What is the human immunodeficiency virus?
- What is the history of HIV?
- What causes an HIV infection?
- What are the different stages of an HIV infection?
- What are risk factors for an HIV infection?
- What are HIV symptoms and signs?
- How do health-care professionals diagnose an HIV infection? What are the different types of HIV tests?
- What are HIV treatments? What medications are used in the treatment of HIV?
- What are complications of an HIV infection?
- What is the prognosis of an HIV infection?
- Is it possible to prevent the transmission of HIV?
- What research is being done on HIV?
- Are support groups available for people who are HIV positive?
- Where can people find more information on HIV?
- HIV-AIDS Rxlist FAQs
- Find a local Infectious Disease Specialist in your town
What are HIV treatments? What medications are used in the treatment of HIV?
Medicines have been developed to inhibit almost all stages of the viral lifecycle. These are called highly active antiretroviral therapy (ART) and include the following:
- Nucleoside and nucleotide reverse transcriptase inhibitors (NRTIs) inhibit the ability of the virus to turn RNA into DNA. These medicines work by blocking the effect of a viral enzyme called reverse transcriptase. The virus needs to make DNA in order to insert it into the human genome. The earliest example of an NRTI was zidovudine (Retrovir), also known as AZT. NRTIs resemble the building blocks of nucleic acids and fool the enzyme into using them, which terminates the DNA strand.
- Non-nucleoside reverse transcriptase inhibitors (NNRTIs) also block the reverse transcriptase enzyme, although in a slightly different way from NRTIs.
- Protease inhibitors (PIs) inhibit a viral enzyme (protease) that the virus uses to turn long strands of protein into usable pieces. Viruses made in the presence of PIs are inactive and ineffective. A PI called ritonavir (Norvir) is used to increase (boost) the potency of other PIs.
- Entry inhibitors were developed to keep viruses from entering cells.
- Integrase inhibitors impair the ability of the transcribed viral DNA to insert into the human genome.
With so many options, it may be surprising that none of these drugs or combinations of these drugs has been shown to cure HIV. The problem lies in the ability of the virus to mutate and become resistant to medications. In addition, copies of the viral DNA can lie quietly in the human genome secluded from the ability of the drugs to act. This creates a latent reservoir for resurgent infection.
Treatment for individual patients depends on the sensitivity of their virus to medications, which can be measured though viral genotyping. Viral genotyping, a kind of drug resistance testing, determines if any anti-HIV medications will not be effective against a person's strain of HIV. Viral genotyping is recommended for all patients in the U.S.
Treatment may need to be individualized to minimize side effects in patients with underlying medical conditions, such as diabetes or heart disease. Pregnant patients should be treated by clinicians who are experts in this area and will not be covered the current article. However, it is important to note that treatment of HIV during pregnancy can dramatically reduce the risk of transmission to the unborn child.
Opinions on when to start ART have evolved over time. In 2013, the National Institutes of Health recommended that ART be given to all patients infected with HIV, regardless of the stage of infection. The goal of this recommendation was to reduce the risk of disease progression and to reduce the risk of contagion. Early treatment can also lead to reduction in HIV-associated inflammation and associated complications, which include cardiovascular and kidney disease. It is important to note that patients on treatment are not cured and can still spread the infection, but treatment reduces the amount of virus in contaminated fluids and therefore reduces the risk of spread.
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