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 (HAART or 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.
What are complications of an HIV infection?
Complications of HIV infection most often stem from impairment of the immune system, especially CD-4 lymphocyte-mediated immunity. As HIV enters stage 3, the immune impairment predisposes patients to AIDS-defining conditions such as infections and cancers. With effective treatment, many patients will not progress to stage 3 infection. There is increasing evidence of direct HIV effects on various end organs and indirect effects via HIV-associated inflammation. End-organ damage may occur at all stages of infection. Although ART is effective in prolonging life and reducing the risk of disease progression, all treatment regimens have side effects, which range from minor problems like fatigue to more serious problems like liver damage.
What is the prognosis of an HIV infection?
Without treatment, HIV infection progresses to AIDS in approximately 10 years, with death following within three years after onset of AIDS. With appropriate treatment, a 20-year-old with HIV infection can expect to live to reach 71 years of age. This dramatic increase in life expectancy emphasizes the need for early diagnosis and treatment. Moreover, with newer treatment regimens and guidelines, there is every reason to think that life expectancy will continue to increase in patients who are able to receive appropriate treatment. There are some factors that decrease life expectancy, including use of illicit drugs and the coexistence of other conditions like chronic hepatitis.
Is it possible to prevent the transmission of HIV?
It's possible to prevent HIV transmission by eliminating sexual intercourse with an infected person and avoiding exposure to potentially contaminated body fluids. Unfortunately, many people with HIV do not know they are infected and inadvertently spread the virus. Treatment can reduce the amount of virus in semen and secretions, but it does not completely eliminate the risk of HIV transmission. A good rule for dating is to assume that sexual partners are infected unless known to be otherwise. Using condoms with every sexual encounter reduces the risk of infection, although it does not eliminate the risk because condoms may break or leak. Needle-exchange programs have reduced the risk of new infection in populations that use illicit drugs. As discussed above, mother-to-child transmission can be dramatically reduced by treating the infected mother during pregnancy, treating the baby at birth, and avoiding breastfeeding. Items that may be contaminated with blood, such as razors or toothbrushes, should not be shared.
There is treatment to prevent transmission using pre-exposure prophylaxis (PrEP). This is when an infected person takes ART because they are at higher risk of acquiring HIV from an infected person, typically a sex partner. This is very effective and commonly available.
Health-care workers who have had a needle stick or other exposure to HIV-contaminated blood should be evaluated to determine whether or not they should take medications as prophylaxis. The types of medicine and the duration of treatment are dependent on the degree of exposure.
What research is being done on HIV?
An extensive amount of research is being done on HIV. Efforts are under way to find an effective vaccine, although this has proved difficult because the virus is not easily killed by traditional human antibodies. New treatments are being developed that scientists hope will be more effective, easier to take, less costly, and/or have fewer side effects. New educational programs may help people avoid risk behaviors or be more compliant with treatment regimens.
Are support groups available for people who are HIV positive?
There are many support groups available for people living with HIV. Clinics that treat people with HIV usually can provide information on local support groups. Most states have support organizations for people with HIV or an HIV hotline that can provide advice on support groups. The federal government's AIDSinfo hotline can be reached at: 800-448-0440. Private support organizations may also be able to help, including those focusing on high-risk populations such as gay men or intravenous drug users. There are many online support groups and chat rooms which can be very helpful if anonymity is desired.
Where can people find more information on HIV?
The best site for current information is http://www.AIDSinfo.nih.gov, which is supported by the National Institutes of Health.
United States. Department of Health and Human Services. "Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents." Jan. 10, 2011. <http://aidsinfo.nih.gov/contentfiles/lvguidelines/adultandadolescentgl.pdf>.