What is Tamiflu (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 is the most important information I should know about Tamiflu (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 discuss with my healthcare provider before taking Tamiflu (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:

• kidney disease
• heart disease
• lung disease
• a condition causing swelling or disorder of the brain; or
• any other serious disease or health problem

FDA pregnancy category C. It is not known whether oseltamivir is harmful to an unborn baby. However, not receiving this medication to prevent influenza could be harmful to the baby if the mother becomes infected with a disease that oseltamivir could prevent. Before taking this medication, tell your doctor if you are pregnant. Your doctor will decide whether you should receive oseltamivir, 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.

Tamiflu Side Effects

What are the possible side effects of Tamiflu (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 side effects to FDA at 1-800-FDA-1088.

Tamiflu Interactions

What other drugs affect Tamiflu (Oseltamivir)?

There may be other drugs 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 should I avoid while taking Tamiflu (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.

Tamiflu Dosage

How should I take Tamiflu (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 overdose on Tamiflu (Oseltamivir)?

Seek emergency medical attention if you think you have used too much of this medicine.
Overdose symptoms may include nausea and vomiting.

What happens if I miss a dose of Tamiflu (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.
Edited from everydayhealth.com