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Drugs reference index «Tamiflu»



Generic name: Oseltamivir phosphateBrand names: Tamiflu

Why is Tamiflu prescribed?

Tamiflu speeds recovery from the flu. When started during the first 2 days of the illness, it hastens improvement by at least a day. It also can prevent the flu if treatment is started within 2 days after exposure to a flu victim. Tamiflu belongs to a class of antiviral drugs called neuraminidase inhibitors.

As the flu virus takes hold in the body, it forms new copies of itself and spreads from cell to cell. Neuraminidase inhibitors fight the virus by preventing the release of new copies from infected cells. Tamiflu is taken in liquid or capsule form.

Most important fact about Tamiflu

Tamiflu can prevent the flu as long as you continue taking Tamiflu, but getting a yearly flu shot is still the best way of avoiding the disease entirely. For older adults, those in high-risk situations such as health-care work, and people with an immune deficiency or respiratory disease, vaccination remains a must.

How should you take Tamiflu?

To provide any benefit, Tamiflu must be started within 2 days of the onset of symptoms, or exposure to the flu. If you have the flu, continue taking it twice daily for 5 days, even if you start to feel better. To prevent the flu, take it once a day for at least 7 days. Protection lasts as long as you take the drug.

If Tamiflu upsets your stomach, try taking it with food. Shake the liquid suspension before each use.

  • If you miss a dose...Take it as soon as possible. If it is within two hours of your next dose, skip the missed dose and go back to your regular schedule.
  • Storage instructions...Store at room temperature. Keep the blister package dry. Use the liquid suspension within 10 days. It should be refrigerated, but do not freeze.

What side effects may occur?

Most problems noted during tests of Tamiflu were indistinguishable from the symptoms of flu. Here are the reactions that showed up more frequently in patients taking the drug.

  • Side effects may include:Abdominal pain, asthma, bronchitis, cough, diarrhea, ear infection, fatigue, headache, insomnia, nausea, nosebleed, vertigo, vomiting

Why should Tamiflu not be prescribed?

If Tamiflu gives you an allergic reaction, avoid it in the future.

Special warnings about Tamiflu

If you have kidney disease, the doctor may have to cut your daily dose of Tamiflu in half.

The effectiveness of Tamiflu has not been established for people with weakened immune systems. The drug has not been studied in people with liver disease.

Tamiflu works only on the flu virus. It won't stop bacterial infections that may have flu-like symptoms or bacterial infections that may develop while you have the flu. If your symptoms persist, check with your doctor.

Possible food and drug interactions when taking Tamiflu

Tamiflu may interfere with the influenza vaccine (flu shot). The flu shot may not provide as much protection if it's received within 2 weeks before or 48 hours after taking Tamiflu.

Special information if you are pregnant or breastfeeding

It is not known whether Tamiflu is completely safe during pregnancy. If you are pregnant or plan to become pregnant, inform your doctor before taking Tamiflu. Tamiflu may appear in breast milk and could affect a nursing infant. Taking it while breastfeeding is usually not recommended.

Recommended dosage for Tamiflu


Treatment of Influenza

The usual dosage is 75 milligrams taken twice daily (morning and evening) for 5 days. If you have kidney disease, take a 75-milligram dose once a day.

Prevention of Influenza

The usual dosage is 75 milligrams taken once a day for at least 7 days. If there is a general outbreak of the flu in your community, your doctor may recommend that you continue taking Tamiflu for up to 6 weeks. If you have kidney disease, take a 75-milligram capsule every other day, or 30 milligrams of liquid once a day.


Treatment of Influenza

Doses should be given twice daily for 5 days using the dispenser that comes with the liquid suspension. Each dose is determined by the child's weight:

Under 33 pounds: 30 milligrams33 to 55 pounds: 45 milligrams51 to 88 pounds: 60 milligramsOver 88 pounds: 75 milligramsTamiflu should not be used to treat the flu in children under 1 year old.

Prevention of Influenza

Tamiflu's ability to prevent the flu in children under age 13 has not been established.


High doses of Tamiflu can cause nausea and vomiting. As with any medication, if you suspect an overdose, seek emergency medical treatment immediately.

  • Tamiflu Prescribing Information (FDA)
  • Tamiflu Advanced Consumer (Micromedex) - Includes Dosage Information
  • Tamiflu MedFacts Consumer Leaflet (Wolters Kluwer)
  • Tamiflu Consumer Overview

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