This drug is used with other HIV medications to help control HIV infection. It helps to decrease the amount of HIV in your body so your immune system can work better. This lowers your chance of getting HIV complications (such as new infections, cancer) and improves your quality of life. Lamivudine belongs to a class of drugs known as nucleoside reverse transcriptase inhibitors-NRTI.

Lamivudine is not a cure for HIV infection. To decrease your risk of spreading HIV disease to others, continue to take all HIV medications exactly as prescribed by your doctor. Use an effective barrier method (latex or polyurethane condoms/dental dams) during sexual activity as directed by your doctor. Do not share personal items (such as needles/syringes, toothbrushes, and razors) that may have contacted blood or other body fluids. Consult your doctor or pharmacist for more details.

This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

This product may also be used to lessen the risk of HIV infection after contact with the virus (for example, due to a needle stick). Ask your doctor for more details.

A lower-strength lamivudine product is used for hepatitis B infection in people without HIV infection.

Read the Patient Information Leaflet if available from your pharmacist before you start taking lamivudine and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth with or without food as directed by your doctor, usually once or twice daily.

The dosage is based on your medical condition and response to treatment. Children's dosage is also based on weight.

It is very important to keep taking this medication (and other HIV medications) exactly as prescribed by your doctor. Do not skip any doses. Do not increase your dose, take this drug more often than prescribed, or stop taking it (or other HIV medicines) even for a short time unless directed to do so by your doctor. Skipping or changing your dose without approval from your doctor may cause the amount of virus to increase, make the infection more difficult to treat (resistant), or worsen side effects.

For the best effect, take this medication at evenly spaced times. To help you remember, take this medication at the same time(s) every day.

See also Warning section.

Headache, dizziness, nausea, diarrhea, or trouble sleeping may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Rarely, lamivudine has caused severe (sometimes fatal) liver problems and a buildup of lactic acid in the blood (lactic acidosis). These serious side effects may occur more often in women and obese patients. Get medical help right away if you have any of the following serious symptoms, including:

• symptoms of liver problems (such as nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine)
• symptoms of lactic acidosis (such as deep/rapid breathing, drowsiness, nausea/vomiting)

As your immune system gets stronger, it can begin to fight off infections you already had, possibly causing disease symptoms to come back. You could also have symptoms if your immune system becomes overactive. This reaction may happen at any time (soon after starting HIV treatment or many months later). Get medical help right away if you have any serious symptoms, including:

• unexplained weight loss
• severe tiredness
• muscle aches/weakness that doesn't go away
• headaches that are severe or don't go away
• joint pain
• numbness/tingling of the hands/feet/arms/legs
• vision changes
• signs of infection (such as fever, chills, swollen lymph nodes, trouble breathing, cough, non-healing skin sores)
• signs of an overactive thyroid (such as irritability, nervousness, heat intolerance, fast/pounding/irregular heartbeat, bulging eyes, unusual growth in the neck/thyroid known as a goiter)
• signs of a certain nerve problem known as Guillain-Barre syndrome (such as unsteadiness, loss of coordination, trouble swallowing/speaking/chewing, trouble moving your eyes)

Tell your doctor right away if you have any serious side effects, including:

• mental/mood changes (such as depression)
• stomach/back pain with nausea (pancreatitis)
• easy bleeding/bruising
• signs of anemia (unusual tiredness, rapid heartbeat, pale/bluish skin)

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking lamivudine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• pancreatitis
• kidney problems
• liver problems (such as hepatitis B or C, cirrhosis)
• alcohol use

Avoid alcoholic beverages because they may increase your risk for liver problems and/or pancreatitis.

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Children may be more sensitive to the side effects of this drug, especially the increased risk of pancreatitis.

Tell your doctor if you are pregnant before using this medication. Treatment can lower the risk of passing HIV infection to your baby. Discuss the risks and benefits with your doctor.

This medication passes into breast milk. Because breast milk may transmit HIV, consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug are:

• orlistat
• sorbitol

Emtricitabine is similar to lamivudine and should not be taken with this medication. Check the labels on all your HIV medicines because they may contain the same ingredients as found in this product. Taking too much of these drugs will not necessarily improve your condition, and may cause more side effects.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab and/or medical tests (such as kidney function, liver tests, viral load, T-cell counts) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Different brands of this medication have different storage needs. Check the product package for instructions on how to store your brand, or ask your pharmacist. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.