Adefovir

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Before taking adefovir,

• tell your doctor and pharmacist if you are allergic to adefovir or any other medications.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention the medications listed in the IMPORTANT WARNING section and probenecid. Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Do not take any other medications while you are taking adefovir unless your doctor has told you that you should.
• do not take adefovir if you are pregnant or plan to become pregnant. If you become pregnant while taking adefovir, call your doctor. Do not breast-feed while taking adefovir.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking adefovir.

Adefovir is an antiviral medication. Adefovir prevents viral cells from multiplying in the body and infecting new liver cells.

Adefovir is used to treat chronic hepatitis B in people who are 12 years of age or older. Adefovir is not a cure for chronic hepatitis B.

Adefovir may also be used for purposes not listed in this medication guide.

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

Early symptoms of lactic acidosis may get worse over time and this condition can be fatal. Get emergency medical help if you have even mild symptoms: muscle pain or weakness, numb or cold feeling in your arms and legs, trouble breathing, stomach pain, nausea with vomiting, fast or uneven heart rate, dizziness, or feeling very weak or tired.

Call your doctor at once if you have:

• little or no urinating;

• swelling, rapid weight gain;

• confusion, loss of appetite, vomiting, pain in your side or lower back; or

• severe stomach pain, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects may include:

• mild stomach pain, diarrhea, gas, indigestion;

• weakness; or

• headache.

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.

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 adefovir, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to adefovir or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of adefovir in children 12 years of age and older. Use is not recommended in children younger than 12 years of age.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of adefovir in the elderly. However, elderly patients are more likely to have age-related kidney or heart problems, which may require caution and an adjustment in the dose for patients receiving adefovir.

Pregnancy

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with 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. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of adefovir. Make sure you tell your doctor if you have any other medical problems, especially:

• Human immunodeficiency virus (HIV) infection or
• Kidney disease or
• Liver disease (including cirrhosis)—Use with caution. May make these conditions worse.

Take adefovir 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 using adefovir without checking first with your doctor.

adefovir comes with patient information leaflet. Read and follow these instructions carefully each time you get more medicine. Ask your doctor or pharmacist if you have any questions.

adefovir works best when there is a constant amount in the blood. To help keep the amount constant, do not miss any doses.

When your adefovir supply runs low, get more from your pharmacy or from your doctor. The amount of virus in your blood may increase if the medicine is stopped, even for a short time. The virus may develop resistance to adefovir and be harder to treat.

You may take adefovir with or without food.

Dosing

The dose of adefovir 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 adefovir. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For oral dosage form (tablets):
  • For chronic hepatitis B infection:
    • Adults and children 12 years of age and older—10 milligrams (mg) once a day.
    • Children younger than 12 years of age—Use is not recommended.

Missed Dose

If you miss a dose of adefovir, 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

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

You should not use adefovir if you are also taking tenofovir (Viread®) or other medicines containing tenofovir (eg, Atripla®, Complera®, Stribild™, or Truvada®). Tell your doctor right away if you are using any of these medicines. Do not start using adefovir until your doctor tells you to.

If you have or get HIV infection, be sure to discuss your treatment with your doctor. If you are using adefovir to treat chronic hepatitis B, and are not taking medicine for your HIV infection at the same time, some HIV treatments may be less likely to work. You may need to get an HIV test before you start using adefovir, and again later if there is a chance you were exposed to HIV. adefovir will not help your HIV infection.

When adefovir is stopped, the liver disease (hepatitis) may become worse. Do not stop using adefovir unless your doctor tells you to. Be sure to keep all appointments with your doctor after you stop using adefovir. Blood tests will be needed to check your liver function.

Check with your doctor right away if you have more than one of the following: blood in the urine, change in frequency of urination or amount of urine, difficulty with breathing, drowsiness, increased thirst, loss of appetite, nausea or vomiting, swelling of the feet or lower legs, or weakness. These may be symptoms of a serious kidney problem.

Two rare but serious reactions to adefovir are lactic acidosis (build-up of acid in the blood) and liver toxicity, including an enlarged liver. These are more common if you are female, very overweight (obese), or have been taking anti-HIV medicines for a long time. Call your doctor right away if you have stomach discomfort or cramping, nausea, vomiting, diarrhea, decreased appetite, muscle cramping or pain, unusual tiredness or weakness, trouble breathing, or a yellowish color in your skin or eyes.

Treatment with adefovir has not been shown to decrease the chance of giving hepatitis B virus infection to other people through sexual contact or by sharing needles. If you have any questions about this, check with your doctor.

• Store at room temperature.
• Store in a dry place. Do not store in a bathroom.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Check with your pharmacist about how to throw out unused drugs.

• If your symptoms or health problems do not get better or if they become worse, call your doctor.
• Do not share your drugs with others and do not take anyone else's drugs.
• Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
• Talk with the doctor before starting any new drug, including prescription or OTC, natural products, or vitamins.
• Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about adefovir, please talk with your doctor, nurse, pharmacist, or other health care provider.
• If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about adefovir. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using adefovir.

Review Date: October 4, 2017

• Antihepadnaviral, Reverse Transcriptase Inhibitor, Nucleotide (Anti-HBV)

May be administered without regard to food.

Manufacturer's labeling: HIV status (prior to initiation of therapy); renal function (prior to initiation and during therapy, especially in patients with risk factors for renal impairment or pre-existing renal impairment); following discontinuation, closely monitor hepatic function with both clinical and laboratory follow-up at repeated intervals for several months following discontinuation of adefovir.

Alternate recommendations: Chronic Hepatitis B: HBV DNA and ALT (HBV DNA usually done every 3 months until undetectable and then every 3 to 6 months thereafter); HBeAg; anti-HBe (in patients who are HBeAg-positive to monitor for seroconversion); HBsAg; creatinine clearance (baseline); if at risk for renal impairment, creatinine clearance, serum phosphate, urine glucose, and urine protein at baseline and at least annually; consider monitoring bone density in patients with risk factors for osteopenia or fracture history (study prior to initiation and during therapy); following discontinuation, monitor for recurrent viremia, ALT flares, seroreversion, and clinical decompensation every 3 months for at least 1 year (AASLD [Terrault 2016]). As antivirals do not eliminate the risk of hepatocellular carcinoma, continued monitoring for this complication is recommended in at-risk patients.

There are no data on the excretion of adefovir dipivoxil into human milk. The manufacturer recommends that due to the potential for serious adverse reactions in nursing infants, a decision should be made to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother. In addition, mothers coinfected with HIV should not breast-feed their infants due to the risk of transmission of HIV via breast milk.

LactMed Record Number

836

Last Revision Date

20160707

Disclaimer

Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.