What is oseltamivir?
Oseltamivir is an antiviral medication that blocks the actions of influenza virus types A and B in
your body.
Oseltamivir is used to treat flu symptoms caused by influenza virus in patients who have had
symptoms for less than 2 days. Oseltamivir may also be given to prevent influenza in people who may
be exposed but do not yet have symptoms. Oseltamivir will not treat the common cold.
Oseltamivir may also be used for other purposes not listed in this medication guide.
What should I discuss with my healthcare provider before taking oseltamivir?
Oseltamivir should not be used in place of getting a yearly flu shot. The Centers for Disease
Control recommends an annual flu shot to help protect you each year from new strains of influenza
virus.
You should not use this medication if you are allergic to oseltamivir.
Before taking oseltamivir, tell your doctor if you have used a nasal flu vaccine (FluMist) within
the past 2 weeks, or if you have:
Vaccines may be harmful to an unborn baby and generally should not be
given to a pregnant woman. However, not vaccinating the mother could be more harmful to the baby if
the mother becomes infected with a disease that this vaccine could prevent. Your doctor will decide
whether you should receive this vaccine, especially if you have a high risk of infection with H1N1
influenza (also called "swine" flu).
It is not known whether oseltamivir passes into breast milk or if it could harm a nursing
baby. Do not take this medication without telling your doctor if you are breast-feeding a baby.
Do not give this medication to a child younger than 1 year old.
How should I take oseltamivir?
Take oseltamivir exactly as your doctor has prescribed it for you. Do not take more of the
medication than recommended. Do not take oseltamivir for longer than your doctor has prescribed.
Treatment with oseltamivir should start as soon as possible when flu symptoms appear, such as
fever, chills, muscle aches, sore throat, and runny or stuffy nose.
Take the oseltamivir
capsule
with a full glass of water.
Shake the
oral suspension
(liquid) well just before you measure a dose.
To be sure you get the correct dose, measure the liquid with the syringe provided with the medicine.
Do not measure the medicine with a regular table spoon. If you do not have the syringe or another
medicine dose-measuring device, ask your pharmacist for one.
You may take oseltamivir with or without food. If the medicine upsets your stomach, it may
help to take it with food or milk.
To
treat
flu symptoms: Take oseltamivir every 12 hours for 5 days.
To
prevent
flu symptoms: Take oseltamivir every 24 hours for 10 days or as
prescribed. Follow your doctor's instructions.
Use this medication for the entire length of time prescribed by your doctor. Your
symptoms may get better before the infection is completely treated. Tell your doctor if your symptoms
do not improve, or if they get worse.
Store oseltamivir capsules at room temperature away from moisture and heat.
Store oseltamivir liquid in the refrigerator but do not freeze. Throw away any unused liquid
after 10 days.
What happens if I miss a dose of oseltamivir?
Take the missed dose as soon as you remember. If your next dose is less than 2 hours away,
skip the missed dose and take the medicine at the next regularly scheduled time.
Do not
take extra medicine to make up the missed dose.
Where can I get more information about oseltamivir?
Your pharmacist has information about oseltamivir written for health professionals that you may read.
What are the possible side effects of oseltamivir?
Stop using oseltamivir and get emergency medical help if you have any of these
signs of an allergic reaction:
hives; difficulty breathing; swelling of your face, lips, tongue,
or throat; a red and blistering or peeling skin rash.
Some people using oseltamivir have had rare side effects of sudden confusion, delirium,
hallucinations, unusual behavior, or self-injury. These symptoms have occurred most often in children.
It is not known whether oseltamivir was the exact cause of these symptoms. However, anyone using
oseltamivir should be watched closely for signs of confusion or unusual behavior. Call a doctor at once
if you or the child using oseltamivir has any of these symptoms.
Less serious side effects may include:
-
nausea, vomiting, diarrhea;
-
dizziness, headache;
-
nosebleed;
-
eye redness or discomfort;
-
sleep problems (insomnia); or
-
cough or other respiratory symptoms.
This is not a complete list of side effects and others may occur. Call your
doctor for medical advice about side effects. You may report vaccine side effects to the US
Department of Health and Human Services at 1-800-822-7967.
What is the most important information I should know about oseltamivir?
Oseltamivir is used to treat flu symptoms caused by influenza virus in patients who have had
symptoms for less than 2 days. Oseltamivir may also be given to prevent influenza in people who may
be exposed but do not yet have symptoms. Oseltamivir will not treat the common cold.
Before taking oseltamivir, tell your doctor if you have received a nasal flu vaccine within the past
2 weeks, or if you have kidney disease, heart disease, lung disease, or any other serious disease or
health problem. Also tell your doctor if you have any condition causing swelling or disorder of the
brain.
Treatment with oseltamivir should start as soon as possible when flu symptoms appear, such as
fever, chills, muscle aches, sore throat, and runny or stuffy nose.
Take this medication for as many days as it has been prescribed for you even if you begin
to feel better. Your symptoms may start to improve before the infection is completely treated.
Some people using oseltamivir have had rare side effects of sudden confusion, delirium,
hallucinations, unusual behavior, or self-injury. These symptoms have occurred most often in children.
It is not known whether oseltamivir was the exact cause of these symptoms. However, anyone using
oseltamivir should be watched closely for signs of confusion or unusual behavior. Call a doctor at once
if you or the child using oseltamivir has any of these symptoms.
Oseltamivir should not be used in place of getting a yearly flu shot. The Centers for Disease
Control recommends an annual flu shot to help protect you each year from new strains of influenza
virus.
What should I avoid while taking oseltamivir?
Do not use a nasal flu vaccine (FluMist) within 48 hours after taking oseltamivir.
Oseltamivir may interfere with the drug action of FluMist, making the vaccine less effective. Follow
your doctor's instructions.
What other drugs will affect oseltamivir?
There may be other that can interact with oseltamivir. Tell your doctor about all the prescription
and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs
prescribed by other doctors. Do not start using a new medication without telling your doctor.
What happens if I have an overdose of oseltamivir?