In the U.S.—

In Canada—

• Antiviral, systemic

Lamivudine (la-MI-vyoo-deen) is used in the treatment of the infection caused by the human immunodeficiency virus (HIV) or hepatitis B virus. HIV is the virus that causes acquired immune deficiency syndrome (AIDS). Lamivudine is taken together with zidovudine (AZT) or other medications used to treat HIV.

Lamivudine will not cure or prevent HIV infection or AIDS; however, it helps keep HIV from reproducing and appears to slow down the destruction of the immune system. This may help delay the development of problems usually related to AIDS or HIV disease. Lamivudine will not keep you from spreading HIV to other people. People who receive this medicine may continue to have other problems usually related to AIDS or HIV disease. Lamivudine is not a cure for the hepatitis B virus; the long-term effects of the drug on the infection and the liver are unknown at this time.

Lamivudine is available only with your doctor's prescription, in the following dosage forms:

Oral
• Oral solution (U.S. and Canada)
• Tablets (U.S. and Canada)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For lamivudine, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to lamivudine. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Lamivudine crosses the placenta. Studies in animals have shown that lamivudine causes birth defects when given in very high doses. Before taking this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant. Ask your doctor to register you with the Pregnancy Registry, to monitor the effect of treatment on you and your baby.

Breast-feeding— Lamivudine passes into the breast milk. If your baby does not already have the AIDS virus, there is a chance that you could pass it to your baby by breast-feeding or your baby could have serious adverse reactions. Talk to your doctor first if you are thinking about breast-feeding your baby.

Children—Lamivudine can cause serious side effects. In one study, children with advanced AIDS were more likely than children who were less ill to develop pancreatitis (inflammation of the pancreas) and peripheral neuropathy (a problem involving the nerves). Therefore, it is especially important that you discuss with your child's doctor the good that this medicine may do as well as the risks of using it. Your child must be seen frequently and your child's progress carefully followed by the doctor while the child is taking lamivudine.

Older adults—Lamivudine has not been studied specifically in older people. Therefore, it is not known whether it causes different side effects or problems in the elderly than it does in younger adults. Talk to your doctor first if you have liver, kidney, heart problems or other diseases. Your doctor may need to adjust your dose.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking lamivudine, it is especially important that your health care professional knows if you are taking any of the following:

• Lamivudine with zidovudine (Combivir)—Should not be used at the same time that you are taking lamivudine tablets or oral solution

• Zalcitabine (Hivid)—May cause problems with how lamivudine or zalcitabine work when used together

• Combined infection of HIV and hepatitis B—May make the condition of either of these infections worse

• Diabetes mellitus (sugar diabetes)—Lamivudine oral solution contains sucrose

• Hepatitis Cor
• Hepatitis delta—Caution should be used; lamivudine safety has not been determined in patients who have hepatitis infections

• Human immunodeficiency virus—For patients with hepatitis B virus, your physician will talk to you about HIV before you begin taking lamivudine. You may be tested for HIV. Lamivudine tablets and oral solution for hepatitis B virus contain lower amounts of the drug than the tablets and solution for HIV. If you start on the lower-dose medication and later learn that you have HIV, the higher-dose lamivudine may not then be effective against the infection caused by HIV.
• Inflamed pancreas or
• Problems with inflamed pancreas in the past or
• Other risk factors for developing an inflamed pancreas or
• Nerve damage—These conditions may occur or worsen when taking lamivudine

• Kidney disease or
• Liver disease or
• Risk factors for liver disease or
• Obesity (being overweight)—Patients with kidney disease may have an increased chance of side effects

• Organ transplant—Caution should be used; lamivudine safety has not been determined in patients who have received an organ transplant

Take this medicine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. Also, do not stop taking lamivudine or zidovudine without checking with your doctor first.

Keep taking lamivudine for the full time of treatment , even if you begin to feel better.

This medicine works best when there is a constant amount in the blood. To help keep the amount constant, do not miss any doses . If you need help in planning the best times to take your medicine, check with your health care professional.

If you are using lamivudine oral suspension, use a specially marked measuring spoon or other device to measure each dose accurately. The average household teaspoon may not hold the right amount of liquid. The lamivudine oral suspension contains sucrose. Tell your doctor if you are diabetic before you start taking this medicine.

Only take medicine that your doctor has prescribed specifically for you. Do not share your medicine with others.

Dosing—

The dose of lamivudine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of lamivudine. Your dose may be different if you have kidney disease. If your dose is different, do not change it unless your doctor tells you to do so:

• For oral dosage forms (oral solution and tablets):
  • For treatment of hepatitis B infection:
    • Adults —100 milligrams (mg) once a day.
    • Children younger than 16 years of age—Use and dose must be determined by your doctor.
  • For treatment of HIV infection or AIDS:
    • Adults weighing 50 kilograms (kg) (110 pounds) or more—150 milligrams (mg) twice a day together with other HIV medications.
    • Adults weighing less than 50 kg (110 pounds)—2 mg per kg of body weight twice a day together with other HIV medications.
    • Children 3 months to 16 years of age—4 mg per kg of body weight, up to 150 mg per dose, twice a day together with other HIV medications.
    • Children younger than 3 months of age—Use and dose must be determined by your doctor.

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

It is very important that your doctor check your progress at regular visits.

Do not take any other medicines without checking with your doctor first. To do so may increase the chance of side effects from lamivudine.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

• More common—especially in children
  • Abdominal or stomach pain (severe);  feeling of fullness;  nausea;  sensation or pins and needles;  skin rash;  stabbing pain;  tingling, burning, numbness, or pain in the hands, arms, feet, or legs;  unsteadiness or awkwardness;  vomiting 
  
  

• Rare
  • Abdominal discomfort;  decreased appetite ;  diarrhea;  fast, shallow breathing;  feeling of fullness;  fever, chills, or sore throat;  general feeling of discomfort;  muscle pain or cramping;  nausea;  shortness of breath;  sleepiness;  unusual tiredness or weakness  
  
  

• Incidence not determined
  • Cough;  dark urine;  difficulty swallowing;  dizziness;  fast heartbeat;  fever;  hives or welts;  itching;  light-colored stools;  puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue;  redness of skin;  tightness in chest;  upper right abdominal pain;  wheezing ;  yellow eyes and skin 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Canker sores;  difficulty in moving;  discouragement;  ear discharge;  ear swelling;  feeling sad or empty;  general feeling of discomfort or illness;  irritability;  loss of appetite;  loss of interest or pleasure;  nasal discharge or congestion;  pain in joints;  sores, ulcers, or white spots on lips or tongue or inside the mouth;  stomach pain or cramps;  swollen and painful spots on neck, armpit, or groin;  swollen joints;  trouble concentrating;  trouble sleeping;  unusually warm skin;  weight loss 
  
  

• Less common
  • Acid or sour stomach;  belching;  cough;  heartburn;  indigestion;  stomach discomfort or upset 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

• Incidence not determined
  • Body fat redistribution or accumulation;  blurred vision;  dry mouth;  flushed, dry skin;  fruit-like breath odor;  hair loss;  increased hunger or thirst ;  increased urination;  sweating;  thinning of hair 
  
  

Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although this use is not included in product labeling, lamivudine is used in certain patients with the following medical condition:

• Human immunodeficiency virus (HIV) infection due to occupational exposure (possible prevention of)

Other than the above information, there is no additional information relating to proper use, precautions, or side effects for this use.