Human Immunodeficiency Virus (HIV) Infection
Medications
Medicines are the primary treatment for HIV. Your doctor will usually prescribe several medicines—this is sometimes called an anti-HIV "cocktail"—that keeps HIV from multiplying and helps keep the immune system healthy. In the past a person had to take several doses of HIV medicine every day, which was difficult for some people. But over the past few years this routine has become much simpler and many people take their medicine for HIV only once or twice a day.
Medicines used to treat HIV are called antiretrovirals, and several of these are combined for treatment called highly active antiretroviral therapy, or HAART. Using HAART reduces your risk of developing resistance to HIV medicines. Resistance is more likely to develop in people who are treated with only one antiretroviral medicine.
When choosing antiretroviral medicines, your doctor will consider certain factors, such as:
- The medicines' effectiveness in reducing viral load.
- The likelihood that the virus will become resistant to a certain class of medicine. If you have already been treated with a certain antiretroviral medicine, you or your doctor may already know whether you have a resistance to medicines in that class.
- Medicine side effects and your willingness to tolerate them.
- The cost of treatment with medicines.
Medicines also are used to prevent other illnesses that can occur with HIV as the result of a weakened immune system. Certain opportunistic infections, such as some types of pneumonia, can develop when HIV attacks and destroys too many CD4+ cells. If too many CD4+ cells are destroyed, the body can no longer fight off infection.
Medication Choices
Antiretroviral therapy
Medicines that prevent HIV from multiplying are called antiretrovirals and include:
- Nucleoside/nucleotide reverse transcriptase inhibitors, such as zidovudine (ZDV, formerly AZT) and stavudine (d4T). These medicines are usually combined for best results.
- Non-nucleoside reverse transcriptase inhibitors (NNRTIs), such as efavirenz, nevirapine, or delavirdine.
- Protease inhibitors (PIs), such as atazanavir, saquinavir, ritonavir, indinavir, nelfinavir, fosamprenavir, lopinavir/ritonavir, tipranavir, or darunavir.
- Fusion inhibitors, such as enfuvirtide.
- Entry inhibitors. The only entry inhibitor approved by Health Canada for the treatment of HIV infection is maraviroc (Celsentri). This medicine is used with other HIV medicines for adults whose current treatments are no longer controlling virus activity.
Other medicines that may be used to treat HIV or AIDS-related conditions include cytokines, such as interferon alfa-2a and interferon alfa-2b.
Treatment failure
If your viral load does not drop as expected, or if your CD4+ cell count starts to fall, your doctor will try to determine why the treatment was not effective.
There are two main reasons that treatment fails:
- The virus that causes HIV has become resistant. The medicine no longer effectively controls virus multiplication nor protects your immune system. Tests can determine whether resistance has occurred. You may need a different combination of medicines.
- You did not take your medicine as prescribed. If you have difficulty taking the medicines exactly as prescribed, talk with your doctor.
What To Think About
You will have frequent blood tests to monitor your CD4+ cell count and viral load while you are taking medicines to treat HIV.
Taking your medicines as prescribed can keep HIV from multiplying and will help prevent other infections. This also can help keep the virus from becoming resistant to the medicines and prevent problems that can limit future treatment options.
Your medicines may have unpleasant side effects, which sometimes make you feel worse than you did before you started taking them. Talk to your doctor about your side effects. He or she may be able to adjust your medicines or prescribe a different one.
Atripla is a medicine that combines efavirenz (Sustiva), emtricitabine (Emtriva), and tenofovir disoproxil fumarate (Viread). Atripla is a pill taken once a day. Atripla is not approved for use in Canada.
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| Author: | Douglas Dana Maria G. Essig, MS, ELS | Last Updated: October 10, 2007 |
| Medical Review: | Adam Husney, MD - Family Medicine Anne C. Poinier, MD - Internal Medicine W. David Colby IV, MSc, MD, FRCPC - Infectious Disease Peter Shalit, MD, PhD - Internal Medicine | |
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