Antiva

Indications

Adefovir Dipivoxil is an antiviral medicine used to treat long-term (chronic) hepatitis B infection in adults whose liver is inflamed or damaged by the virus. It is mainly used when the virus has become resistant to Lamivudine, or together with Lamivudine. Newer medicines such as Tenofovir and Entecavir are now often preferred.

How It Works

In the body, Adefovir Dipivoxil is changed into Adefovir, which blocks an enzyme (DNA polymerase) that the hepatitis B virus needs to copy itself. This lowers the amount of virus in the blood and reduces liver damage. It controls the infection but does not cure it.

Dosage and Administration

Adults: 10 mg once daily by mouth, with or without food. People with reduced kidney function need a lower frequency, as set by the doctor. Treatment is usually long-term; take it exactly as prescribed and do not stop on your own.

Interactions

Avoid use with Tenofovir. Medicines that can harm the kidneys, such as Aminoglycosides (for example Gentamicin), Vancomycin, Ciclosporin, Tacrolimus and regular high doses of pain killers like Ibuprofen, increase the risk of kidney damage. Tell your doctor about all medicines you take.

Contraindications

Do not take if you are allergic to Adefovir or any ingredient of the tablet.

Side Effects

• Weakness and tiredness
• Headache
• Nausea, stomach pain, wind or diarrhoea
• Rise in kidney test values (creatinine), especially with long-term use
• Low blood phosphate

Get urgent medical help if you notice yellowing of the skin or eyes, dark urine, severe tummy pain, much less urine than usual, or unusual muscle pain with fast breathing and severe tiredness (signs of lactic acidosis, a rare build-up of acid in the blood).

Pregnancy and Lactation

Use in pregnancy only if the doctor decides the benefit is greater than the risk. Women who could become pregnant should use effective contraception. Breastfeeding is not recommended while taking this medicine.

Precautions and Warnings

Your kidney function and liver tests will be checked regularly. Stopping treatment can cause a sudden, severe flare of hepatitis, so never stop without medical advice. Have an HIV test before starting, because Adefovir alone can make HIV resistant to treatment. It does not prevent passing hepatitis B to others.

Overdose

Taking too much may cause stomach upset. Contact a doctor or hospital promptly; kidney function may need to be checked.

Therapeutic Class

Antiviral; nucleotide analogue reverse transcriptase inhibitor for hepatitis B.

Storage

Store below 30°C in a dry place, away from light and out of the reach of children. Keep the container tightly closed.