What medicines are used for HIV infection?
There are several kinds of medicines are used to fight HIV infection. The first kind is called nucleoside analog reverse transcriptase (say trans-krip-tase) inhibitors, or "nukes." When HIV infects a healthy cell, it needs the cell's DNA, or genetic instructions, to build copies of itself. These drugs act by blocking the HIV's ability to copy a cell's DNA. Without complete DNA, HIV can't make new virus copies. These medicines include the following:
- Tenofovir DF
- Combination of Abacavir, Lamivudine and Zidovudine
- Combination of Abacavir and Lamivudine
- Combination of Emtricitabine and Tenofovir DF
- Combination of Lamivudine and Zidovudine
The second kind of medicine is called a non-nucleoside reverse transcriptase inhibitor. These drugs also prevent HIV from using a healthy cell's DNA to make copies of itself, but in a slightly different way. This group includes the following medicines:
The third kind of medicine is called protease (say pro-tee-ase) inhibitors. These medicines work by preventing infected cells from releasing HIV into the body. This group includes the following medicines:
- The combination of Lopinavir and Ritonavir
The fourth kind of medicine is called a fusion inhibitor. This medicine works by preventing the entry of the HIV virus into your body's healthy cells. This medicine is injected by a doctor. This group includes the following medicines:
The last type of medicine is called an integrase inhibitor. This medicine works by disabling integrase. Integrase is a protein that HIV uses to insert its genetic material into the genetic material of CD4 cells. This group includes the following medicine:
The different kinds of medicines are often used together (in combination) to reduce the amount of HIV in the body.
When different drugs are combined with the purpose of reducing the amount of HIV in your blood to very low levels, the resulting treatment regimen is called highly active antiretroviral therapy (HAART). Your doctor must watch you closely when you are being treated with these drugs to see how well they lower the amount of virus in your body. Your doctor also wants to make sure you aren't having side effects like nausea, vomiting, fatigue, anemia or peripheral neuropathy (a numb feeling in your hands or feet).
How does the doctor tell if the medicines are working?
Three tests can measure the amount of the virus in your blood. Your doctor can use this information to find out how your body is responding to the medicine.
- The CD4 cell count. CD4 cells are a kind of white blood cell (sometimes called T-lymphocytes, or T-cells) in your blood. CD4 cells are important because they help your body fight infections. Unfortunately, these cells are also the main target of the virus that causes HIV infection. This virus cripples the CD4 cells. In people who don't have HIV, the CD4 level is between 500 and 1,200 cells per mm3 (cubic millimeter). Your doctor will probably give you medicine to fight HIV when your CD4 cell count drops below a certain level. One goal of treatment for HIV infection is to keep your CD4 cell count as high as possible.
- Viral load. The viral load is the number of copies of HIV in your blood. A person who doesn't have HIV infection has a viral load of 0. Medicine that lowers the amount of HIV in the body is usually given when your viral load measures more than 10,000 to 30,000 viral copies per mL (milliliter) of blood. A second goal of treatment is to make the viral load as low as possible.
- CBC. The complete blood count (also called the CBC) measures the number of red and white cells in your blood. Red blood cells carry oxygen from your lungs to all the tissues of your body. White blood cells fight infections. They keep your body's immune system strong. A large drop in red blood cells and a large drop in white blood cells can occur when HIV infection is getting worse. This drop can also be caused by the same medicines that you take to fight HIV (medicines like zidovudine). Your doctor uses the CBC to help decide when to change your medicines. Your doctor wants to keep your red and white blood cell counts high enough to keep you healthy.
What happens during a routine office visit?
Your doctor will check several things to find out how strong your HIV infection has become. Your doctor will ask you about your symptoms. He or she will look for any signs that the HIV infection is getting worse. Your doctor will also do a blood test to check your CD4 cell count and your viral load. Some of the things that might tell your doctor that your HIV infection has gotten worse since your last visit are the following:
- New symptoms of nausea, vomiting, fatigue, fever, headache, chills, night sweats, cough, shortness of breath or diarrhea.
- Signs of weight loss, mouth sores (such as thrush, which is a yeast infection) or bigger lymph nodes (glands located in your neck, armpits and hip area).
- A drop in the CD4 cell count in your blood.
- A rise in the viral load in your blood.
How often will my doctor want to see me?
Your doctor will probably want to see you every 6 months as long as your CD4 cell count is higher than 500. Your doctor will probably want to see you every 3 months if your CD4 cell counts are below 500. However, if you take a new medicine, your doctor will want to see you more often, to check your response to the medicine or to see if your HIV infection is getting worse.
What else can help me?
Some medicines can help prevent the other infections and complications that come when HIV lowers your body's resistance (makes your immune system weak). Here are some things that can help people with HIV:
- A flu shot every fall helps prevent the flu.
- A shot every 5 to 7 years can prevent pneumonia caused by the bacteria called Streptococcus pneumoniae. It's easier for people who have HIV to get this kind of pneumonia.
- A tuberculosis (TB) skin test every year can tell if you have TB. TB is a very serious illness, especially in people who have HIV.
- A Pap test for women to check for dysplasia (a pre-cancer condition) and for cancer of the cervix. Both of these conditions occur more often in women who have HIV infection. At first, Pap tests are done every 6 months. After 2 Pap tests in a row are normal, you might only have to get them once a year.
- A hepatitis B test for people who are at risk for hepatitis B infection. You're at risk for this infection if you inject drugs. If the test shows you don't have hepatitis B infection, your doctor might want you to have the hepatitis B vaccine to protect you from getting the infection.
- A medicine called TMP-SMZ can help. This antibiotic would be given to you if your CD4 cell count is less than 200. It helps prevent pneumonia caused by a bacteria called Pneumocystis jiroveci. This antibiotic also helps prevent another infection, called toxoplasmosis.
- Azithromycin, clarithromycin and rifabutin can help when your CD4 cell count is lower than 50 to 75. They keep you from getting an infection caused by a bacteria called Mycobacterium avium.
What is the best time to start taking these medicines?
Almost all experts agree that medicines for HIV should be started before the person's CD4 cells fall under 200. Most doctors want their patients to start taking medicines earlier, when the CD4 cell count is between 200 and 500. You and your doctor should talk about which medicines to take and when to start taking them.
Which are the best drugs for me to use?
Each person should talk to his or her doctor about the medicines for HIV. Most doctors treat their patients with more than one medicine.
Your doctor will test your blood to see when you should start taking medicine. The blood tests can also show how well your medicine is working. The tests will help your doctor decide if your treatment should change.
Where can I get more information about HIV treatments?
Many cities have telephone hotlines for both patients and the general public. Look for the number in your telephone yellow pages, under AIDS information.
What's in the future?
Combination drug therapy has changed HIV disease from the leading killer of young adults to a chronic disease that can be controlled for decades. However, even though you can take HIV medicines and feel okay, you could still give the virus to others through unsafe sex or blood exchanges. The medicines don't kill the virus -- they just keep your immune system strong enough to prevent AIDS or slow it down.
New medicines are being developed and tested that can be taken less often and that are more powerful in holding back the virus. However, it may be a few years before these new drugs become available.
Written by familydoctor.org editorial staff