Viraflu

Indications

Favipiravir is an antiviral medicine. It was first approved for new or re-emerging strains of influenza (flu) when other flu medicines do not work. In Bangladesh and some other countries it has also been used, on a doctor's prescription, for mild to moderate COVID-19. Evidence of benefit for COVID-19 is limited, and it should only be used when a doctor prescribes it.

How It Works

Inside the body Favipiravir is changed into an active form that blocks RNA polymerase, an enzyme many viruses need to copy themselves. This slows the spread of the virus in the body.

Dosage and Administration

As prescribed. Treatment usually starts with a higher loading dose on the first day, followed by a lower dose twice a day for a short course, commonly 5 to 14 days depending on the illness. Take the tablets by mouth, with or without food, and complete the course the doctor gives. It is not recommended for children.

Interactions

Tell the doctor about all medicines, especially: Pyrazinamide (uric acid may rise further); Theophylline (raises Favipiravir levels); Repaglinide and Paracetamol (Favipiravir can raise their levels, so the Paracetamol dose may need to be limited); and Famciclovir and Sulindac (their effect may be reduced).

Contraindications

• Pregnancy or possible pregnancy.
• Allergy to Favipiravir or any ingredient of the product.

Side Effects

Common: raised uric acid in the blood, diarrhoea, nausea, raised liver enzymes and a fall in white blood cells. Less often: rash, vomiting and stomach pain.

Get urgent medical help for: signs of a serious allergic reaction (swelling of the face or throat, difficulty breathing, widespread rash), yellowing of the skin or eyes, severe or bloody diarrhoea, sudden painful swollen joints, or unusual or confused behaviour.

Pregnancy and Lactation

Favipiravir can cause serious birth defects and early pregnancy loss. It must not be used in pregnancy. A pregnancy test should be done before starting if pregnancy is possible. Women who could become pregnant must use reliable contraception during treatment and for at least 7 days after the last dose. Men should use condoms during treatment and for at least 7 days after, because the medicine passes into semen. It passes into breast milk, so breastfeeding should be stopped during treatment and for 7 days after the last dose.

Precautions and Warnings

• Tell the doctor about gout or high uric acid, liver disease, or kidney disease.
• Blood tests may be needed during treatment.
• It does not replace vaccination or other treatments the doctor advises.

Overdose

Information is limited. Too much may increase side effects such as raised uric acid and liver problems. Seek medical help promptly.

Therapeutic Class

Antiviral (RNA polymerase inhibitor).

Storage

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