Lamivudine and tenofovir are antiviral medicines that prevent human immunodeficiency virus (HIV) from multiplying in your body.

Lamivudine and tenofovir is a combination medicine used to treat HIV, the virus that can cause acquired immunodeficiency syndrome (AIDS). Lamivudine and tenofovir is not a cure for HIV or AIDS.

lamivudine and tenofovir is used in adults and children who weigh at least 77 pounds.

Lamivudine and tenofovir may also be used for purposes not listed in this medication guide.

lamivudine and tenofovir can cause serious side effects. Call your doctor at once if you have symptoms such as upper stomach pain, loss of appetite, dark urine, yellowing of your skin or eyes, bone pain, or muscle weakness.

You may develop lactic acidosis, a dangerous build-up of lactic acid in your blood. Call your doctor or get emergency medical help if you have unusual muscle pain, trouble breathing, stomach pain, dizziness, feeling cold, or feeling very weak or tired.

If you've ever had hepatitis B, it may become active or get worse after you stop using lamivudine and tenofovir. You may need frequent liver function tests for several months.

Your doctor will perform blood tests to make sure you do not have conditions that would prevent you from safely using lamivudine and tenofovir.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

You may take lamivudine and tenofovir with or without food.

You will need frequent medical tests. Your kidney and liver function may also need to be checked.

Lamivudine and tenofovir doses are based on weight in children. Your child's dose needs may change if the child gains or loses weight.

Use all HIV medications as directed and read all medication guides you receive. Do not change your dose or dosing schedule without your doctor's advice. Every person with HIV should remain under the care of a doctor.

Store in the original container at room temperature, away from moisture and heat.

If you've ever had hepatitis B, this virus may become active or get worse in the months after you stop using lamivudine and tenofovir. You may need frequent liver function tests while using this medicine and for several months after your last dose.

Usual Adult Dose for HIV Infection:

1 tablet orally once a day

Use: In combination with other antiretroviral agents, for the treatment of HIV-1 infection

Usual Pediatric Dose for HIV Infection:

At least 35 kg: 1 tablet orally once a day

Use: In combination with other antiretroviral agents, for the treatment of HIV-1 infection

You should not use this medicine if you are allergic to lamivudine or tenofovir.

Tell your doctor if you have ever had:

• liver disease, including cirrhosis or hepatitis B or C (especially if you also use ribavirin or interferon alfa);

• kidney disease (or if you are on dialysis);

• a pancreas disorder; or

• bone problems, including osteoporosis or a broken bone.

You may develop lactic acidosis, a dangerous build-up of lactic acid in your blood. This may be more likely if you have other medical conditions, if you've taken HIV medication for a long time, or if you are a woman. Ask your doctor about your risk.

Tell your doctor if you are pregnant, and use your medications properly to control your infection. HIV can be passed to your baby if the virus is not controlled during pregnancy. Your name may be listed on a registry to track any effects of antiviral medicine on the baby.

Women with HIV or AIDS should not breastfeed a baby. Even if your baby is born without HIV, the virus may be passed to the baby in your breast milk.

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

Get your prescription refilled before you run out of medicine completely.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

Unless your doctor tells you otherwise, continue your normal diet.

Avoid taking other medications that contain an ingredient called sorbitol, often used as a sweetener in liquid medicines. Ask your pharmacist if you are not sure a medicine contains this ingredient.

Using lamivudine and tenofovir will not prevent your disease from spreading. Do not have unprotected sex or share razors or toothbrushes. Talk with your doctor about safe ways to prevent HIV transmission during sex. Sharing drug or medicine needles is never safe, even for a healthy person.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Lamivudine and tenofovir may cause serious side effects. Call your doctor at once if you have:

• new or worsening bone pain;

• muscle weakness;

• pain in your arms, hands, legs, or feet;

• swelling around your midsection;

• kidney problems--little or no urination, swelling in your feet or ankles, feeling tired or short of breath; or

• signs of liver or pancreas problems--loss of appetite, upper stomach pain (that may spread to your back), nausea or vomiting, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Lamivudine and tenofovir affects your immune system, which may cause certain side effects (even weeks or months after you've taken this medicine). Tell your doctor if you have:

• signs of a new infection--fever, night sweats, swollen glands, cold sores, cough, wheezing, diarrhea, weight loss;

• trouble speaking or swallowing, problems with balance or eye movement, weakness or prickly feeling; or

• swelling in your neck or throat (enlarged thyroid), menstrual changes, impotence.

Common side effects of lamivudine and tenofovir may include:

• headache;

• pain;

• diarrhea;

• rash;

• depression; or

• changes in the shape or location of body fat (especially in your arms, legs, face, neck, breasts, and waist).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Lamivudine and tenofovir can harm your kidneys, especially if you also use certain medicines for infections, cancer, osteoporosis, organ transplant rejection, bowel disorders, high blood pressure, or pain or arthritis (including Advil, Motrin, and Aleve).

Tell your doctor about all your other medicines, especially other antivirals to treat HIV or hepatitis C.

Other drugs may affect lamivudine and tenofovir, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Keep a supply of lamivudine and tenofovir on hand. Do not wait until you run out of medication to refill your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.