An Introduction to Tamiflu
Tamiflu
® (
oseltamivir phosphate) is a prescription medication used for the prevention or treatment of
the flu. It is licensed for adults and children 1 year of age and older. The medication is not a
flu vaccine, nor should it be used in place of a yearly flu vaccination.
The Food and Drug Administration has authorized emergency use of Tamiflu for infants under one year of age for the 2009-2010 H1N1 flu season.
It is manufactured by Roche Pharmaceuticals.
Tamiflu has been licensed for two uses:
- Treatment of influenza (the virus that causes the flu)
- Prevention of influenza.
For Tamiflu to treat the flu, it must be taken within one to two days of the start of
flu symptoms. For prevention, it must also be started as soon as possible after exposure.
Tamiflu has not been shown to be effective against other types of viruses, including viruses that cause the
stomach flu or
common cold. It is actively being studied to learn how effective it is at treating
bird flu (
avian flu).
The medication works by attacking the
flu virus inside the body, thus preventing it from spreading. This is different from other
flu medicines, which just treat symptoms of the flu.
Tamiflu is part of a class of drugs called neuraminidase inhibitors. Neuraminidase (an enzyme found on the flu virus) allows the flu virus to spread. By blocking this enzyme, Tamiflu limits the virus's ability to spread.
When and How Do I Take Tamiflu?
Here are some general considerations for when and how to take it:
- Tamiflu comes in either liquid or capsule form. It is taken once or twice a day, depending on your healthcare provider's instructions. You may take it with or without food. If it upsets your stomach, take it with food.
- It should be taken at the same time each day to maintain an even level of the medication in your blood.
- Make sure that you complete your entire prescription of the medication, even if you start feeling better before it's finished. This will ensure that the infection is completely treated.
The dosage your healthcare provider recommends will vary, depending on a number of factors, including:
- Your age
- Other medical conditions you may have.
As is always the case, do not adjust your dose unless specifically instructed by your healthcare provider to do so.
(The side effects listed below are not a complete list of possible side effects you may experience with Tamiflu. Your healthcare provider can give you a more complete list.)
As with any medicine, there are possible side effects with Tamiflu. However, not everyone who takes it will experience side effects. In fact, most people tolerate the drug quite well.
For adults, the most common Tamiflu side effects are:
In children, the most common side effect is vomiting; up to 15 percent of children experience this side effect.
Nausea and vomiting usually happen during the first couple of days of treatment, and are usually mild to moderate. Taking Tamiflu with food may help decrease the chances of developing these side effects.
If you develop an allergic reaction or severe skin rash, stop taking Tamiflu and call your healthcare provider.
Drug Interactions With Tamiflu
What Should I Tell My Healthcare Provider?
Prior to taking this medication, you should tell your healthcare provider if you have:
- Liver disease or liver failure
- Kidney disease or kidney failure
- Heart disease
- Liver disease
- Allergies to any medicines.
Let your healthcare provider know if you are:
- Pregnant or thinking about becoming pregnant
- Breastfeeding.
Also, tell your healthcare provider about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements.
What If I Take an Overdose?
If you happen to overdose on Tamiflu, seek immediate medical attention.
How Should Tamiflu Be Stored?
It should be stored at room temperature, away from moisture. Also, keep Tamiflu and all medications out of the reach of children. Tamiflu suspension (liquid) should be discarded after ten days after it is mixed by your pharmacist.
What Should I Do If I Miss a Dose?
If you do not take your Tamiflu as scheduled, take it as soon as you remember, unless it is almost time for your next scheduled dose. If it is almost time for your next scheduled dose, skip the one you forgot and take your next dose instead. Never take a double dose.
Strengths
Tamiflu comes in the following strengths and forms:
- Tamiflu 30 mg capsules
- Tamiflu 45 mg capsules
- Tamiflu 75 mg capsules
- Tamiflu for oral suspension (liquid), containing 12 mg of Tamiflu per mL.
For situations when Tamiflu suspension is unavailable (such as during a shortage), your pharmacist may need to make a suspension using the capsules. In this situation, the suspension strength will be 15 mg per mL (not the standard 12 mg per mL as with the commercially available suspension).
There is currently no generic Tamiflu available for sale.
