3TC, trade name Epivir (also known as lamivudine), is an anti-HIV treatment in the same class of drugs as AZT, ddI, ddC and d4T. These drugs are called nucleoside analogs. The body breaks down these drugs into chemicals that stop HIV from infecting uninfected cells in the body, but they do not help cells that have already been infected with the virus. As people with HIV lose CD4 cells cells - one of the immune systems main defenses - they become more likely to get infections and illnesses.

3TC is an important part of combination anti-HIV treatment. Ideally, 3TC should be used as part of a carefully chosen combination of anti-HIV treatments in order to get the most benefit. Studies have shown that when taken alone 3TC has a strong anti-HIV effect at first, but the virus can quickly become resistant. The anti-HIV effects may then wear out. Many studies have now shown that using 3TC in combination with at least two other anti-HIV drugs can prevent the virus from getting resistant. This has helped people live longer and develop less opportunistic infections. Drug resistance tests (genotypic or phenotypic) have been shown to be useful in choosing the optimal anti-HIV treatment regimen specific to an individual. See the FactSheets "Combination Therapy" & "Understanding Drug Resistance" for a detailed discussion on these subjects.

New Public Health Service HIV treatment guidelines say that the best way to use 3TC is in combination with other anti-HIV drugs. The guidelines recommend combinations of three or four anti-HIV drugs as first treatment for HIV:

• Two nucleoside analogs (AZT+3TC, d4T+3TC, d4T+ddI, AZT+ddI, or AZT+ddC) with one of the following: Crixivan, Fortovase, Norvir, Sustiva, Viracept, or Norvir and Fortovase combined in lower than usual doses.
• If one of the above combinations cannot be used, an alternative is two nucleoside analogs (same combinations as listed above) with Viramune or Rescriptor.

3TC is also approved for the treatment of hepatitis B (Epivir HBV). Studies have shown that 3TC can reduce the amount of hepatitis B virus to very low levels, although this effect does not always last. The treatment of Hepatitis B will likely require using combination therapy.

Dosage:
The recommended dosage of 3TC is 150 mg twice a day. 3TC is also available in a syrup form for children. 3TC can be taken with or without food. There are also two new pills that combines 3TC with other nucleoside analog drugs, making it easier to take. Combivir combines 150mg of 3TC with 300mg of AZT. Trizivir contains the above plus 300 mg of abacavir. People who are allergic to abacavir should not take Trizivir. See the"abacavir (Ziagen)" FactSheet for detailed information about the potentially severe and sometimes fatal allergic reactions associated with this drug.

Side effects:
3TC has few side-effects, mainly nausea, vomiting, headaches, and rare cases of hair loss. Although not as commonly as with some other anti-HIV drugs, 3TC can cause damage to the nerves in the hands and feet. This condition is called peripheral neuropathy. The symptoms of peripheral neuropathy are burning or numbing sensations in the hands and feet which can become very painful. If 3TC causes this problem, it may be necessary to switch to another anti-HIV drug to prevent permanent nerve damage. See the FactSheet "Peripheral Neuropathy" for other treatment options which might be helpful.

3TC can cause a side effect called pancreatitis, especially in children. Pancreatitis is a dangerous swelling of an organ in the body called the pancreas. People taking 3TC should be carefully monitored for this side effect.

Warning:
A set of rare but serious side effects of nucleoside analog anti-HIV drugs is called lactic acidosis and severe hepatomegaly with steatosis (an enlarged fatty liver). Women, especially those who are oveweight, are particularly at risk. This set of side effects is probably the result of mitochondrial toxicity. Mitochondria are cell's power organs that supply the energy needed for normal cell growth. Anti-HIV nucleoside analogs impair the function of mitochondria. This can lead to increased acid levels in the blood, and an enlarged fatty liver. The symptoms are severe nausea, shortness of breath and vomiting that does not get better. If you are taking anti-HIV drugs and experience these symptoms, tell your provider immediately.

Warning:
If you're going to use 3TC, it's important to check for infection with hepatitis B. If you have active hepatitis B when you start 3TC, you may feel sick for a month or two because liver cells infected with hepatitis B die off. Liver enzymes may also increase temporarily. These symptoms are a lot like some drug side effects, and knowing your hepatitis status can help tell the difference. There have also been several reports of hepatitis B flare-ups when 3TC treatment is stopped. Symptoms of hepatitis B flare-ups are high liver enzymes, yellow skin (jaundice), nausea, vomiting, fatigue, abdominal and joint pain.

Call The Network at 212-260-8868 or 800-734-7104 for more information on Hepatitis and HIV co-infection.

GlaxoSmithKline, the maker of 3TC (Epivir), has a patient assistance program for people having problems getting the drug. The number to call is (800) 722-9294. People that have been receiving the drug through the expanded access program and who now need help with reimbursement should call (800) 513-3028. To find out if a drug is covered by your state's AIDS Drug Assistance Program or Medicaid, call The Access Project at (800) 734-7104.