Adefovir (Oral)

Adefovir is used to treat chronic hepatitis B' virus (HBV) in sufferers who are at least 12 years of age. The medicine will not cure HBV, but it can help to control the virus and prevent it from multiplying.


This medication is known under the brand name Hepsera in the US. Hepsera is only available on prescription from a health professional or from your doctor.

Adefovir is a nucleotide analog medication that is used to treat chronic hepatitis B' virus in patients over 12 years of age. The medication works by retarding the growth and spread of the virus and by lowering the amount of the virus that is present in the body. The medication is not a cure for HBV and it does not prevent sufferers from passing the virus to others.

The medication is only available through prescription from your doctor or other medical professional and comes in tablet form.

Conditions treated

  • Chronic Hepatitis B' virus (HBV)

Type of medicine

  • Nucleotide analog tablet

Side effects

This medication is designed to control the symptoms of your condition, however you may experience some unwanted side effects while you are using it. Before you start taking Adefovir, always tell your doctor if you have ever experienced any side effects or allergic reactions to any form of medication, including over-the-counter products, supplements or herbal preparations. You must also inform your doctor if you have any known allergies to particular foods, preservatives, dyes or animals.

The side effects outlined below have been experienced by some patients taking Adefovir. However, it should be noted that this list is not exhaustive and if you notice anything out of the ordinary about your behavior or if you begin to feel unwell after you start taking this medicine, you must consult your medical professional or pharmacist immediately.

Some of the more commonly experienced side effects in patients taking Adefovir include a feeling of general lethargy, drowsiness and weakness. This can be accompanied in some people by nausea and vomiting, stomach and right upper abdomen pain, stools that are unusually light in color, dark urine, and jaundice (yellowing of the skin and eyes).

Less commonly, changes in the frequency of urination and amount of urine produced, together with the presence of blood in the urine have been noted. Other side effects include a loss of appetite and increased thirst, swelling of the lower legs and feet, breathing difficulties, muscle cramps and pain. You may also feel generally unwell or in discomfort.

The following side-effects have also been experienced by patients who are taking Adefovir:

  • bloating
  • fractures of the bones, especially of the femur (thigh bone)
  • aches and pains in the bones
  • chills, fever, and flu-like symptoms
  • cloudy or darkened urine
  • constipation
  • seizures or convulsions
  • rapid or fluctuating heart beat
  • hypertension (high blood pressure)
  • indigestion
  • pain in the lower back and sides
  • muscular pain, wasting, weakness or tenderness
  • abdominal pain, radiating to the back, sides, and stomach
  • swelling of the face and fingers
  • weight gain
  • acid reflux
  • biliousness, excessive gas or air in the stomach
  • diarrhea

If you do experience any of the above side effects when you begin taking Adefovir, you may find that they resolve themselves within a few weeks as your body adjusts to the new medication. Your doctor may be able to suggest ways in which you can prevent or reduce some of the more bothersome side effects.

Not all patients experience side-effects when taking this medication, but you should always consult your healthcare professional if you have any questions or concerns about any side effects you may experience. It should also be noted that many of the side effects reported by HBV patients mimic the symptoms of the actual disease.


The dose of this medicine will vary between patients. Always take your medication in line with your doctor's instructions or refer to the directions on the product label. The following dosage information is based on the average prescribed dose. The dose you are prescribed will depend on the strength of the medication. The number of tablets you are required to take each day and the time allowed between doses may also vary. If you are prescribed a different dose, do not change it unless you are told to do so by your doctor.

Do not skip or miss any doses. If you do miss a dose, do not take double the quantity.

For the treatment of chronic (long-term) hepatitis B' infection in adults and children 12 years of age and over: 10 mg, once a day.

Adefovir is not recommended for use in children under 12 years of age, and your doctor will discuss an alternative drug therapy with you if appropriate.

If you inadvertently miss your prescribed dose of this medicine, you should try to take it as soon as possible. However, if your next dose is almost due, do not double-up. Instead, you should revert to your usual dosing schedule.

In the case of accidental overdose, if the affected person develops serious side effects such as losing consciousness or severe breathing difficulties, you should call 911. If an overdose occurs but no side effects are evident, consult your doctor or call a poison control centre immediately.

Adefovir works best when levels of the medicine are maintained in the blood. In order to keep the amount constant, try not to miss any doses and take your medication at the same time each day. When your supply of medication starts to get low, be sure to order more from your doctor or pharmacy so that you do not run out. Avoiding gaps in your dose regimen is very important as the amount of the virus that is present in your blood may increase if you miss your medication, even for a very short period. If you neglect to take your medication regularly at the correct dose, the hepatitis B' virus may become resistant to Adefovir, making it more difficult and potentially problematic to treat.

You may take this medication with or without food.

Drug interactions

Although some medicines should never be used together, in other cases it may be appropriate to use two or more different medicines, even though an interaction may occur. In this case, your health professional may elect to alter the dose or may suggest that you take other precautions.

You should always tell your doctor immediately if you are prescribed Adefovir and you are also taking any other medication, including herbal preparations, vitamin supplements or over-the-counter medicines. You should not use some medications when you are eating certain types of foods, or if you are using tobacco or alcohol as this may cause interactions to occur. Under these circumstances, you should discuss the use of this medication with your doctor before you begin taking it.

There are some products that may interact with this medication, including:

  • cidofovir
  • non-steroidal anti-inflammatory drugs (for example, ibuprofen)

You should never take any medication that contains tenofovir with Adefovir.

If you suffer from other medical conditions, the efficacy of this medication may be affected, so be sure to inform your doctor of any existing health problems that you have.

Note that Adefovir should be used with extreme caution if you suffer from any of the following conditions, as its prolonged use may make these health problems worse:


In addition to discussing any allergies and other drugs that you are taking, it is important that you also mention to your doctor any existing health conditions that you have, before you start taking Adefovir.

The use of Adefovir is not recommended in children under 12 years of age.

Caution should be exercised when prescribing Adefovir to geriatric patients as they are more prone to kidney or heart problems, which may require adjustment of the dose.

Do not take this medicine if you are already taking products containing tenofovir.

If you are pregnant or breastfeeding, there may be a risk to your unborn baby. Always tell your doctor if you are pregnant or nursing or if you are planning on becoming pregnant, before you begin using the medication.

It is advisable to have a HIV test before you begin using Adefovir and again subsequently if you think that you may have been exposed to HIV. This medication may affect the efficacy of some HIV treatments, meaning that they are less likely to work. Adefovir will not help in treating a HIV infection.

While you are taking this medication and after you have been told to discontinue it, you will be required to attend your doctor for regular blood tests and check-ups. You must attend these appointments as they are necessary to check your liver function.

If you experience more than one of the following symptoms, you should contact your doctor immediately as they could indicate a serious kidney problem that has been caused by the medication:

  • blood in the urine
  • change in frequency of urination and amount of urine
  • increased thirst
  • swelling of the feet or lower legs

There are two rare but extremely serious reactions to this medicine: lactic acidosis and liver toxicity. These are more commonly seen in overweight female patients, or in those who have been taking anti-HIV medication for a prolonged period. If you experience any of the following symptoms, contact your doctor urgently:

  • stomach or muscle cramps
  • nausea or vomiting
  • diarrhea
  • loss of appetite
  • jaundice
  • breathing difficulties
  • feelings of extreme tiredness or weakness

Patients taking Adefovir should not assume that the treatment will reduce the likelihood of passing the hepatitis B' virus infection to other people. Do not share needles with other people and always use a condom when having sex. Your doctor will provide you with more information and advice about this.


Always keep your medication at room temperature and in a sealed, airtight container.

This medication is not suitable for freezing.

Do not place the medication where it will be exposed to direct sunlight and keep it away from heat sources, such as radiators or fires. Do not get the medication wet.

Keep the medication away from pets and children. In the event that a pet consumes Adefovir, seek veterinary advice immediately.

Never use Adefovir that has exceeded its use-by date or if the packaging appears to be damaged.

Ask your doctor or pharmacist for advice on how to dispose of any unwanted or out-of-date medication. Do not flush the leftover tablets down the toilet, put them down the drain, or throw them out with your garbage where they could be found by children or animals.


Adefovir is a nucleotide analog medication that's effective in the treatment of chronic hepatitis B' virus in patients over 12 years of age. The medication is not a cure for HBV and it does not prevent sufferers from passing the virus to others.

Sufferers of HBV experience unpleasant symptoms including feelings of extreme fatigue, fevers, aches and pains, and a general feeling of being unwell. Patients also feel nauseous and experience problems with upset stomachs, diarrhea, and abdominal pain. Adefovir can be very effective in relieving these symptoms, giving sufferers a much-improved quality of life.

Adefovir is highly effective and beneficial to patients, however it is important that you communicate fully with your doctor. This medication cannot prevent the transmission of hepatitis B' virus to other people and it is therefore crucial that you discuss with your doctor the precautions that you should take to avoid this, especially if you take drugs or are in a high risk group for HIV.

The medication helps to slow down the growth of the virus within the body, thus alleviating the symptoms and preventing the condition from becoming worse. To achieve the best results, it is important that you work closely with your doctor to find the appropriate dose and frequency of use.

Last Reviewed:
December 10, 2017
Last Updated:
April 27, 2018