WARNING

Adefovir is an antiviral medication primarily used to treat chronic hepatitis B infection. Like all medications, it comes with a range of potential risks and side effects. Here’s a detailed look at the risks associated with adefovir:

• Renal Toxicity: Adefovir can cause kidney problems, including nephrotoxicity. This can manifest as an increase in serum creatinine levels or a decrease in kidney function. Regular monitoring of kidney function is essential for patients on adefovir.
• Lactic Acidosis: Though rare, adefovir may lead to lactic acidosis, a serious condition characterized by the buildup of lactic acid in the blood. Symptoms of lactic acidosis include rapid breathing, nausea, vomiting, and abdominal pain. If you experience these symptoms, seek medical attention immediately.
• Hepatotoxicity: While adefovir is used to treat liver conditions, it can also cause liver problems in some patients. This can include worsening of hepatitis or liver damage, particularly if the medication is stopped suddenly.
• Bone Mineral Density Loss: Long-term use of adefovir may result in decreased bone mineral density, potentially leading to bone pain, osteoporosis, or fractures.
• Resistance Development: Like other antiviral drugs, adefovir can lead to the development of drug-resistant strains of hepatitis B virus. This is more likely to occur if the medication is not taken as prescribed or if there are issues with drug absorption.
• Gastrointestinal Issues: Some patients may experience gastrointestinal side effects, including nausea, diarrhea, or abdominal pain.
• Headache and Fatigue: Headaches and fatigue are common side effects and may affect daily functioning.
• Liver Enzyme Abnormalities: Elevated liver enzymes can occur, indicating potential liver inflammation or damage.

Patients taking adefovir should have regular check-ups with their healthcare provider to monitor for these potential side effects and ensure the medication is working effectively. It’s also important to follow the prescribed dosage and not stop the medication abruptly without medical advice.

Why is this medication prescribed?

Adefovir is an antiviral medication primarily prescribed to treat chronic hepatitis B, a viral infection that affects the liver. The drug works by interfering with the hepatitis B virus (HBV) replication process, thereby helping to reduce the amount of the virus in the body, which can prevent liver damage, including cirrhosis and liver cancer.

How should this medicine be used?

Here are some general guidelines:

• Dosage: Adefovir is usually taken orally, in tablet form, once daily. The dosage may vary based on the patient’s condition and response to treatment. It’s essential to follow the doctor’s prescription precisely.
• With or Without Food: Adefovir can be taken with or without food.
• Duration of Treatment: The duration of treatment is often long-term and may continue for several months or even years. Stopping the medication abruptly can lead to a rebound of the virus, so it should only be stopped under a doctor’s guidance.
• Monitoring: Regular monitoring of liver function and viral load is necessary while on Adefovir to assess the effectiveness and any potential side effects.
• Hydration: It’s advisable to stay well-hydrated while taking this medication.

If you have any concerns about missed doses or how to manage your medication, consult your healthcare provider for advice tailored to your situation.

Other uses for this medicine

• Treatment of Lamivudine-resistant Hepatitis B: Adefovir may be used when hepatitis B does not respond to other antiviral drugs like Lamivudine.
• Off-label Uses: In some cases, Adefovir might be considered for off-label uses, which means it’s used in a manner not specified in the official prescribing information, under the guidance of a healthcare provider.

What special precautions should I follow?

When using Adefovir, certain precautions are essential to ensure safety and effectiveness:

• Medical History: Provide your doctor with a complete medical history, especially if you have a history of kidney disease, liver disease (other than hepatitis B), or any other serious medical conditions.
• Current Medications: Discuss all medications, supplements, and herbal products you are currently taking to avoid interactions.
• Kidney Function Monitoring: Adefovir can affect kidney function, especially in higher doses or in patients with pre-existing kidney issues. Regular kidney function tests may be necessary.
• Liver Function Monitoring: Regular liver function tests are crucial since stopping Adefovir suddenly can lead to severe exacerbation of hepatitis B. The doctor will monitor your liver function periodically.
• Avoid Stopping Medication Abruptly: Do not stop taking Adefovir without your doctor’s advice. Abrupt discontinuation can cause a sudden increase in hepatitis B virus levels, potentially leading to severe liver problems.
• Pregnancy and Breastfeeding: If you are pregnant, planning to become pregnant, or breastfeeding, consult your doctor. Adefovir can affect the fetus, so it is crucial to discuss the risks and benefits with your healthcare provider.
• Lactic Acidosis and Hepatomegaly: Adefovir can cause lactic acidosis (a buildup of lactic acid in the blood) and hepatomegaly (enlarged liver) with steatosis (fatty liver). Symptoms like unusual muscle pain, trouble breathing, stomach pain, dizziness, and feeling very cold or tired should be reported immediately.
• Regular Follow-up: Regular follow-ups with your healthcare provider are essential to monitor your response to treatment and manage any potential side effects.
• Avoid Alcohol: Alcohol can increase the risk of liver damage. It is advisable to avoid alcohol while taking Adefovir.
• Missed Dose Instructions: If you miss a dose, take it as soon as you remember unless it’s almost time for your next dose. Do not double up to make up for a missed dose.
• Use in Children: The use of Adefovir in children should be closely monitored and is usually based on the child’s weight and specific health condition.

These precautions help in minimizing risks and ensuring that the treatment is as safe and effective as possible.

What special dietary instructions should I follow?

• Normal Diet: There are no specific dietary restrictions associated with Adefovir. You can generally continue with your regular diet.
• Hydration: It’s important to stay well-hydrated while on Adefovir, especially if you are at risk of kidney issues.
• Avoid Alcohol: As mentioned, avoid alcohol to reduce the risk of liver damage.

What should I do if I forget a dose?

• Take It as Soon as You Remember: If you forget a dose, take it as soon as you remember.
• Skip If Close to Next Dose: If it’s almost time for your next dose, skip the missed dose and take the next dose at the regular time.
• Do Not Double Up: Do not take a double dose to make up for the missed one, as this can increase the risk of side effects.

What side effects can this medication cause?

Adefovir, like all medications, can cause side effects. While not everyone experiences them, it’s important to be aware of potential side effects and to consult your healthcare provider if you notice any concerning symptoms.

Common Side Effects:

• Headache
• Nausea
• Diarrhea
• Weakness
• Abdominal pain

These side effects are usually mild and may go away as your body adjusts to the medication.

Serious Side Effects: Some side effects of Adefovir can be serious. Contact your doctor immediately if you experience any of the following:

• Kidney Problems: Signs include decreased urination, swelling of the ankles or feet, or unexplained weight gain.
• Liver Problems: Symptoms may include yellowing of the skin or eyes (jaundice), dark urine, light-colored stools, nausea, vomiting, and loss of appetite.
• Lactic Acidosis: A rare but serious condition where lactic acid builds up in the blood. Symptoms include unusual muscle pain, trouble breathing, stomach pain with nausea and vomiting, cold or blue hands and feet, dizziness, or feeling very weak or tired.
• Bone Pain or Softening: Long-term use of Adefovir may lead to bone problems, including bone pain or softening, which could increase the risk of fractures.

Allergic Reactions: In rare cases, Adefovir can cause an allergic reaction. Seek emergency medical attention if you experience:

• Rash, itching, or swelling (especially of the face, tongue, or throat)
• Severe dizziness
• Difficulty breathing

When Adefovir is stopped, there is a risk of liver symptoms worsening. Your doctor will monitor your liver function closely after discontinuation. Stopping the medication early can lead to drug resistance, which can make the virus harder to treat in the future.

Always report any new or worsening symptoms to your healthcare provider. They can help manage side effects and adjust your treatment plan if necessary.

What should I know about storage and disposal of this medication?

Storage and Disposal of Adefovir:

Storage:

• Store Adefovir at room temperature, typically between 20°C and 25°C (68°F and 77°F).
• Keep it in its original container, tightly closed, and away from moisture and light.
• Do not store in the bathroom or any area prone to moisture.
• Keep the medication out of reach of children and pets.

Disposal:

• Do not flush Adefovir down the toilet or pour it into a drain unless instructed to do so.
• If the medication is expired or no longer needed, dispose of it through a medicine take-back program if available.
• If no take-back programs are accessible, consult your pharmacist or local waste disposal company for guidance on proper disposal.

In case of emergency/overdose

• Symptoms: Overdose symptoms may include severe weakness, nausea, vomiting, stomach pain, diarrhea, or reduced urine output.
• Immediate Action: If an overdose is suspected, contact emergency medical services or go to the nearest emergency room immediately.
• Poison Control Center: You can also call the Poison Control Center at 1-800-222-1222 in the United States for guidance.

What other information should I know?

• Medication Adherence: Take Adefovir exactly as prescribed by your healthcare provider. Do not skip doses or stop taking it without consulting your doctor, as this can lead to a worsening of your condition or resistance to the medication.
• Regular Monitoring: Regular blood tests may be needed to monitor kidney function and to check for any potential side effects.
• Interactions: Inform your healthcare provider about all other medications, supplements, or herbal products you are taking, as Adefovir can interact with other drugs.
• Pregnancy and Breastfeeding: Inform your doctor if you are pregnant, planning to become pregnant, or breastfeeding. Adefovir should only be used during pregnancy if clearly needed, and it is not recommended while breastfeeding.
• Missed Dose: If you miss a dose of Adefovir, take it as soon as you remember. If it is almost time for the next dose, skip the missed dose; do not double up to make up for a missed one.
• Side Effects: Common side effects include headache, stomach pain, and nausea. Serious side effects may include kidney problems, liver issues, and lactic acidosis. Contact your doctor if you experience unusual or severe symptoms.

Always consult your healthcare provider for personalized medical advice.