Adefovir: what it treats, how to take it, side effects
Last updated September 7, 2026.
**Adefovir is a prescription antiviral in the nucleotide analog class used to treat chronic hepatitis B.** It blocks the virus from copying itself. Do not stop without your prescriber's guidance because hepatitis B can worsen sharply afterward.
What does it treat?
You may be prescribed adefovir dipivoxil for chronic hepatitis B with ongoing viral activity and liver inflammation shown by testing, even without symptoms. It does not cure the infection. MedlinePlus reports that adefovir has been discontinued in the US, so contact your prescriber about replacement treatment before your supply runs out.
How do you take it?
The labeled adult dose with adequate kidney function is one 10 mg tablet by mouth daily, with or without food; never exceed 10 mg daily. Kidney impairment requires longer intervals between doses. For daily dosing, take a missed dose when remembered that day; if remembered the next day, skip it. Never double up. Stop taking it and get immediate medical help for symptoms of lactic acidosis, such as extreme weakness with rapid breathing.
Side effects to know
- Common: You may experience headache, weakness, nausea, stomach pain, gas, diarrhea, or indigestion.
- Serious: Stop taking adefovir and seek immediate help for extreme weakness with rapid breathing or severe abdominal swelling, which can signal lactic acidosis or serious liver injury. Reduced urination, swelling, or new bone pain requires prompt assessment for kidney damage.
Who should not take it?
Do not take it if you are allergic to adefovir or its ingredients. Review kidney disease, other liver disease, HIV status, and all medicines with your doctor; HIV testing is recommended before treatment. Avoid combining it with tenofovir disoproxil fumarate. Discuss pregnancy and breastfeeding first: current labeling describes insufficient pregnancy data and unknown effects on breastfed infants. Avoid alcohol because you have hepatitis B.
When is it an emergency?
For overdose, call Poison Control at 1-800-222-1222 immediately, even without symptoms; stomach upset or discomfort can occur. Call 911 for collapse, breathing trouble, or throat swelling suggesting anaphylaxis. Extreme weakness with rapid breathing or confusion needs emergency evaluation for lactic acidosis.
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Common questions
What is the maximum daily dose?
Do not exceed 10 mg daily. With adequate kidney function, you take one 10 mg tablet daily. Kidney disease can require less frequent dosing.
Can I drink alcohol?
Avoid alcohol with hepatitis B. It adds stress to your liver. Ask your clinician for help if avoiding alcohol is difficult.
Can I take it while pregnant or breastfeeding?
Contact your prescriber to review treatment. Current labeling says pregnancy data are insufficient to assess risk. Breast milk transfer and effects on infants are unknown, so you and your clinician must weigh breastfeeding benefits and treatment needs. Do not stop on your own.
Do I need to take it with food?
You can take it with or without food. Choose a consistent time for your prescribed schedule. Do not take an extra tablet after a missed dose.
What are the signs of overdose?
You may have stomach upset or discomfort. Call Poison Control at 1-800-222-1222 immediately after an overdose, even if you feel well. Call 911 for collapse or breathing trouble.
Which medicines need an interaction check?
Do not combine adefovir with tenofovir disoproxil fumarate, including combination pills containing it. Ibuprofen, naproxen, tacrolimus, cyclosporine, and certain antibiotics can increase kidney concerns. Have your pharmacist review every medicine and supplement before adding anything.