Vironil

Indications

Tenofovir Disoproxil Fumarate is an antiviral medicine used to treat long-term (chronic) hepatitis B infection in adults and children, and HIV-1 infection together with other HIV medicines. It is also used, as part of a doctor-supervised programme, to lower the risk of getting HIV (pre-exposure prophylaxis). It does not cure HIV or hepatitis B.

How It Works

Viruses such as HIV and hepatitis B need an enzyme called reverse transcriptase (or polymerase) to copy themselves. Tenofovir blocks this enzyme, which lowers the amount of virus in the blood and helps protect the liver and the immune system.

Dosage and Administration

Adults: usually 300 mg once a day, by mouth, with or without food, or as prescribed. Children and people with kidney problems: as prescribed, since the dose or timing may need to change. Take it at the same time every day and do not miss doses. Do not stop taking it without speaking to the doctor.

Interactions

• Medicines that can harm the kidneys, such as Gentamicin and other aminoglycosides, Amphotericin B, Acyclovir in high doses, and regular high-dose painkillers like Diclofenac or Ibuprofen, increase the risk of kidney damage.
• Do not use with other medicines that contain Tenofovir or with Adefovir.
• Some hepatitis C medicines (such as Ledipasvir and Sofosbuvir combinations) and some HIV medicines raise tenofovir levels; extra kidney monitoring may be needed.
• Didanosine should not be combined with it.

Contraindications

Allergy to tenofovir or any ingredient of the product.

Side Effects

Common: nausea, vomiting, diarrhoea, headache, dizziness, tiredness, rash and low phosphate in the blood. With long-term use it can affect the kidneys and reduce bone strength, so regular tests are needed.

Get urgent medical help if you have: yellow skin or eyes, dark urine, pale stools or severe tiredness (possible liver problem); fast or deep breathing, severe muscle pain, stomach pain with vomiting and unusual weakness (possible lactic acidosis, which is rare but serious); passing much more or much less urine than usual; or signs of a serious allergic reaction such as swelling of the face or trouble breathing.

Pregnancy and Lactation

Tenofovir is widely used in pregnancy, under medical care, to treat HIV and hepatitis B and to lower the chance of passing infection to the baby. Do not stop it on your own if you become pregnant; speak to your doctor. Breastfeeding advice depends on the infection and local guidelines, so discuss it with your doctor.

Precautions and Warnings

• Stopping treatment in hepatitis B can cause a sudden, severe flare of liver inflammation; liver tests are needed for several months after stopping.
• People with hepatitis B should be tested for HIV before starting, and HIV treatment must always include other medicines, to avoid resistance.
• The doctor will check kidney function before and during treatment, and may check bone health.
• Tell the doctor about kidney disease, bone disease or liver disease.
• It does not prevent passing HIV or hepatitis B to others through sex or blood; use condoms and do not share needles, razors or toothbrushes.

Overdose

If too much has been taken, contact a doctor or go to hospital. Treatment is supportive, and the medicine can be removed partly by dialysis.

Therapeutic Class

Antiviral; nucleotide reverse transcriptase inhibitor.

Storage

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