HIV and AIDS
How is it treated?
AIDS has no cure and there are currently no FDA-approved vaccines to protect against HIV, but there are vaccines that are currently being studied. However, medications can slow the progress of the disease, which allows patients to stay healthier and live longer. The drugs used to treat HIV infection are called antiretrovirals, because they fight HIV, which is a type of "retrovirus."
The goals of therapy are to:
- Suppress viral load (or the amount of HIV in a sample of blood)
- Restore or preserve immune function
- Improve quality of life
- Reduce morbidity (the occurrence of opportunistic infections or number of hospitalizations) and mortality (death)
The four types of currently FDA-approved antiretroviral medications used to treat HIV and AIDS are:
- Nucleoside Reverse Transcriptase Inhibitors (NRTIs), which includes Nucleotide Analogs
- Non-nucleoside Reverse Transcriptase Inhibitors (NNRTIs)
- Protease Inhibitors
- Fusion Inhibitors, sometimes also referred to as Entry Inhibitors
How These Drugs Work:
Antiretroviral drugs inhibit the growth and replication of HIV at various stages of its life cycle. NRTIs interrupt an early stage of the virus replication process (or interrupt the virus from making copies of itself). NRTIs help to slow the spread of HIV in the body and delay the start of other opportunistic infections. NNRTIs keep the enzyme called "reverse transcriptase" from working so viral cells cannot reproduce. Protease Inhibitors interrupt virus replication at a later step in the HIV life cycle. Nucleotide Analogs prevent the HIV cells from producing new virus and decrease the amount of HIV in the body. Fusion Inhibitors bind to HIV and prevent the virus from infecting healthy cells in the body.
Recommended Treatment Options:
According to the guidelines for the use of antiretroviral agents,
- treatment is typically not started in individuals who have a CD4+ T cell count of greater than 350 cells/mm3 and plasma HIV RNA levels of less than 100,000 copies/mL.
- clinicians may consider starting therapy for individuals who have a CD4+ count of more than 350 cells/mm3 and a plasma HIV RNA level of more than 100,000 copies/mL and are not showing signs or symptoms of HIV, whereas some clinicians may choose to delay starting therapy.
- individuals who have a CD4+ count of 201to 350 cells/mm3 and any level of plasma HIV RNA are offered the option to start treatment, but it is up to the individual.
- treatment is recommended in those individuals who have a CD4+ count of less than 200 cells/mm3 are not showing signs or symptoms of HIV/AIDS.
- treatment is recommended in those individuals that have severe symptoms of HIV infection or have a history of AIDS-defining illnesses (such as multiple/recurrent bacterial infections, recent pneumonia, fungal infection in the esophagus, herpes simplex virus, kaposi?s sarcoma-a type of skin cancer, burkitt?s lymphoma-a type of cancer, invasive cervical cancer, as well as any other opportunistic infections just to name a few) no matter what their CD4+ count is.
Highly Active Anti-Retroviral Therapy (HAART) is a combination of different classes of drugs that are used to treat HIV/AIDS. This therapy focuses on maximizing suppression of the individual?s symptoms of HIV and prolonging the development of opportunistic infections. The treatment guidelines recommend two different types of regimens for those individuals who have not been placed on HAART before. Both regimens include the use of 2 NRTI?s as the basis of therapy. One of the regimens recommends the additional use of 1 NNRTI agent (so, 2 NRTI?s plus 1 NNRTI) while the other recommends the additional use of 1 to 2 PI?s (so, 2 NNRTI?s plus 1 to 2 PI?s). Studies have shown that the combination of zidovudine, lamivudine (both are NRTI?s ), and efavirenz (an NNRTI) is a regimen that is superior over other regimens for initial therapy.
Unfortunately, the HIV/AIDS virus typically becomes resistant to medications due to viral mutations or changes. Also, over time, individuals may become intolerant to the medication or the medication?s side effects which can be very unpleasant. With resistance developing or if medication intolerance occurs, 1 to 2 medications might have to changed at some point during therapy.
Non-FDA Approved Medications:
Researchers are currently studying a new class of antiretroviral drugs called Integrase Inhibitors. Integrase inhibitors work by blocking the ?integration? of HIV viral genetic material into the genetic material of the host cell. MK-0518 is a drug that falls into this class of drugs and will mainly being used in those individuals who are resistant to the other 4 classes of antiretroviral medications. Initial testing of this potential therapy has shown good effectiveness and safety. Individuals who are resistant to at least 1 medication from each of the following classes: NRTI, NNRTI, and PI, may be able to get early access to this medication through Merck Pharmaceutical?s (the maker of MK-0518) expanded access research program (EARMRK). There is also a new drug in the NNRTI class that is being studied for its activity against those who have developed resistance to other NNRTIs. This medication is referred to as TMC-125 and is available through Tibotec?s expanded access program.
Combination Medications:
Due to the need of a large number of medications used to treat HIV, drug companies have started to create combination medications. Some of these combination medications contain up to three different HIV medication ingredients to help reduce the number of pills taken per day and to help individuals remember to take all medications. Here is a list of all currently available combination medications: Trizivir, Epzicom, Truvada, Combivir, and Atripla. Some of the combination medications contain drugs from the same class, but not all of them.
Resistance Testing:
When individuals who are infected with HIV become resistant to a particular treatment regimen, a new regimen should be tried. But how do doctors know if the new treatment will work? Persons who fail a certain combination of antiretroviral drugs can undergo resistance testing (sometimes called ?genotype testing?) before starting a new treatment regimen. This type of testing may help health care providers find the most effective treatment regimen for the resistant infection. Also, since resistant HIV can be transmitted to others, some newly diagnosed patients who have not been on antiretroviral drugs previously may also undergo resistance testing to find the most appropriate drugs even before beginning treatment.
The treatment guidelines provide recommendations on when an individual should have resistance testing done. Resistance testing should be performed in those individuals who:
- have an acute HIV infection and therapy is going to be started (often times an acute infection goes unrecognized as it presents with similar symptoms to the flu and other illnesses, symptoms include: fever, rash, headache, nausea/vomiting, weight loss. HIV RNA tests are done to then confirm diagnosis.)
- have a chronic HIV infection and therapy is going to be started
- have suboptimal viral load reduction
Resistance testing should be considered in those individuals who have an acute HIV infection, but therapy is going to be started at a later time. However, resistance testing may not be beneficial for all patients with HIV/AIDS. Your doctor can decide if resistance testing is right for you.
Finally, it is important to note that individuals who are infected with HIV should seek medical care from doctors who are specially trained and have expertise in treating HIV/AIDS. We are learning more and more about HIV/AIDS on a daily basis. Research into new drug therapies and treatments is ongoing. Seeking medical care from an HIV/AIDS specialist will help you ensure that you are receiving the most cutting-edge therapy and care. An HIV/AIDS specialist will best be able to determine when to start HIV treatment and what HAART regimen is best.
To learn more about the different drug classes used to treat HIV/AIDS, click on the links below.
Drug classes used to treat HIV and AIDS Combination Antiretroviral Medications Fusion Inhibitors Non-Nucleoside Reverse Transcriptase Inhibitors Nucleoside Reverse Transcriptase Inhibitors (NRTIs) Nucleotide Analogs Protease Inhibitors
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How is it treated?
