A hepatitis B antiviral
Adefovir
An older hepatitis B tablet that controls the virus long term but needs kidney monitoring.
What is Adefovir?
Adefovir is an older antiviral tablet used to control chronic hepatitis B. It suppresses the virus and protects the liver, but like other hepatitis B medicines it controls rather than cures the infection, so it is taken long term. Its main caution is that it can affect the kidneys, so kidney function is monitored during treatment. It must not be stopped suddenly, as this can trigger a flare of hepatitis. It is prescribed and supervised by a specialist liver or infection team.
Education and reference only. This is a plain-language guide to Adefovir — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Adefovir is an older antiviral used to treat long-term (chronic) hepatitis B, a virus that infects the liver and can, over many years, cause scarring (cirrhosis) and liver cancer. Like other hepatitis B medicines, it usually keeps the virus suppressed and the liver protected rather than curing the infection, so it is taken long term. Newer hepatitis B medicines are often preferred now, but adefovir (the brand Hepsera is well known) is still used in some situations. It is taken as a once-daily tablet and is started and overseen by a specialist liver or infectious-diseases team.
How it works
Adefovir blocks the enzyme that hepatitis B uses to copy its genetic material inside liver cells, so the virus can no longer reproduce effectively. As the virus level in the blood falls, liver inflammation settles and the long-term risk of damage drops. Because the virus is suppressed rather than fully cleared, it can become active again if treatment stops, which is why adefovir is taken long term and should not be stopped without specialist advice.
Company & origin
Originated / developed by: Gilead Sciences.
An older antiviral developed for chronic hepatitis B, used in the UK to keep the virus under control, with kidney monitoring.
Practical use
How to take Adefovir
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it once a day at around the same time, as directed by your specialist team, with or without food.
- Do not stop it without your team's advice, as stopping can trigger a flare of hepatitis.
- Keep up with your regular blood tests, which check both your kidneys and your liver.
- Tell your team about any existing kidney problems or other medicines that can affect the kidneys.
- Stay well hydrated and report changes such as much less urine or swelling, which can signal kidney effects.
Weighing it up
Advantages & disadvantages of Adefovir
Advantages
- Suppresses chronic hepatitis B and helps protect the liver over the long term.
- Taken as a simple once-daily tablet.
- A useful option in some situations where it remains appropriate.
Disadvantages
- Can affect the kidneys, so kidney function must be monitored throughout treatment.
- Controls rather than cures the infection and must not be stopped suddenly.
- Often less preferred now than newer, more potent hepatitis B medicines.
Practical use
Good to know
Chronic hepatitis B is usually controlled rather than cured, and adefovir is one of the medicines used to do that, although newer options are often chosen first. The main practical caution is its effect on the kidneys: it can reduce kidney function over time, so regular blood tests check the kidneys throughout treatment, and the dose may be spaced out or changed if needed. As with all hepatitis B treatment, it must not be stopped suddenly, because the virus can rebound and cause a flare of hepatitis that occasionally becomes severe; any stopping is planned and monitored. Taken consistently and with monitoring, it helps protect the liver over the long term.
Who should not take it / use with caution
- People with significant kidney impairment use it only with care, monitoring and adjusted timing.
- It is used cautiously alongside other medicines that can affect the kidneys.
- Stopping it is avoided except under specialist supervision because of the risk of a hepatitis flare.
Monitoring
- Regular blood tests to check kidney function throughout treatment.
- Blood tests to track the hepatitis B virus and liver function over time.
- Review of other medicines that can affect the kidneys.
Side effects
- Headache, tiredness and stomach upset are the most common effects and are usually mild.
- Reduced kidney function over time, which is why kidney tests are done regularly.
- Rarely, a flare of hepatitis if the medicine is stopped suddenly, which needs urgent attention.
Key interactions
- Other medicines that can affect the kidneys may add to its effect on kidney function.
- Medicines cleared by the kidneys can interact, so your team will review everything you take.
- Its use must be coordinated with any HIV treatment, which your specialist team will manage.
Available as: Tablets taken by mouth.
Answers
Adefovir: frequently asked questions
Will adefovir cure my hepatitis B?
It controls the virus and protects the liver rather than curing the infection, so it is taken long term.
Why do I need kidney tests?
Adefovir can affect kidney function over time, so regular blood tests check your kidneys and the dose can be adjusted if needed.
Can I stop it when I feel better?
No. Stopping suddenly can cause the virus to rebound and trigger a flare of hepatitis, so any change is planned and monitored by your specialist team.
Is adefovir still commonly used?
Newer hepatitis B medicines are often preferred now, but adefovir is still used in some situations where it remains appropriate.
Should I drink plenty of fluids?
Staying well hydrated is sensible, and you should report changes such as passing much less urine or new swelling, which can signal kidney effects.
The wider class
About Hepatitis B antiviral (nucleotide)
Adefovir belongs to the hepatitis b antiviral (nucleotide) class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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