Oseltamivir is used to treat some types of influenza infection ('flu') in adults, children, and infants (older than 2 weeks of age) who have had symptoms of the flu for no longer than 2 days. This medication is also used to prevent some types of flu in adults and children (older than 1 year of age) when they have spent time with someone who has the flu or when there is a flu outbreak. Oseltamivir is in a class of medications called neuraminidase inhibitors. It works by stopping the spread of the flu virus in the body. Oseltamivir helps shorten the time that flu symptoms such as a stuffy or runny nose, sore throat, cough, muscle or joint aches, tiredness, headache, fever, and chills last. Oseltamivir will not prevent bacterial infections, which may occur as a complication of the flu.
Oseltamivir comes as a capsule and a suspension (liquid) to take by mouth. When oseltamivir is used to treat flu symptoms, it is usually taken two times a day (morning and evening) for 5 days. When oseltamivir is used to prevent flu, it is usually taken once a day for at least 10 days, or for up to 6 weeks during a community flu outbreak. Oseltamivir may be taken with or without food, but is less likely to cause upset stomach if it is taken with food or milk. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part that you do not understand. Take oseltamivir exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
It is important to know the dose of medication your doctor has prescribed and to use a measuring device that will measure the dose accurately. If you are taking the medication yourself or giving it to a child older than 1 year of age, you can use the device provided by the manufacturer to measure the dose according to the instructions below. If you are giving the medication to a child under one year of age, you should not use the measuring device provided by the manufacturer because it cannot accurately measure small doses. Instead, use the device provided by your pharmacist. If the commercial suspension is unavailable and your pharmacist prepares a suspension for you, he or she will provide a device to measure your dose. Never use a household teaspoon to measure doses of oseltamivir oral suspension.
Shake the suspension well (for about 5 seconds) before each use to mix the medication evenly.
Open the bottle by pushing down on the cap and turning the cap at the same time.
Push the plunger of the measuring device completely down to the tip.
Insert the tip of the measuring device firmly into the opening on the top of the bottle.
Turn the bottle (with the measuring device attached) upside down.
Pull back on the plunger slowly until the amount of suspension prescribed by your doctor fills the measuring device to the appropriate marking. Some larger doses may need to be measured using the measuring device twice. If you are not sure how to correctly measure the dose your doctor has prescribed, ask your doctor or pharmacist.
Turn the bottle (with the measuring device attached) right-side up and slowly remove the measuring device.
Take oseltamivir directly into your mouth from the measuring device; do not mix with any other liquids.
Replace the cap on the bottle and close tightly.
Remove the plunger from the rest of the measuring device and rinse both parts under running tap water. Allow the parts to air dry before putting back together for the next use.
Call your doctor or pharmacist to find out how you should measure a dose of oseltamivir suspension if you do not have the measuring device that came with this medication.
Hold the capsule over a small bowl and carefully pull open the capsule and empty all of the powder from the capsule into the bowl. If your doctor has instructed you to take more than one capsule for your dose, then open the correct number of capsules into the bowl.
Add a small amount of sweetened liquid, such as regular or sugar-free chocolate syrup, corn syrup, caramel topping, or light brown sugar dissolved in water to the powder.
Stir the mixture.
Swallow the entire contents of this mixture right away.
Continue to take oseltamivir until you finish the prescription, even if you start to feel better. Do not stop taking oseltamivir without talking to your doctor. If you stop taking oseltamivir too soon or skip doses, your infection may not be fully treated, or you may not be protected from the flu.
If you feel worse or develop new symptoms while taking oseltamivir, or if your flu symptoms do not start to get better, call your doctor.
Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.
Oseltamivir may be used to treat and prevent infections from avian (bird) influenza (a virus that usually infects birds but can also cause serious illness in humans). Oseltamivir also may be used to treat and prevent infections from influenza A (H1N1).
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
If you forget to take a dose, take it as soon as you remember it. If it is no longer than 2 hours before your next scheduled dose, skip the missed dose and continue your regular dosing schedule. If you miss several doses, call your doctor for directions. Do not take a double dose to make up for a missed one.
rash, hives, or blisters on the skin
swelling of the face or tongue
difficulty breathing or swallowing
hallucinations (seeing things or hearing voices that do not exist)
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].
Keep this medication in the container it came in and out of reach of children. Store the capsules at room temperature and away from excess heat and moisture (not in the bathroom). Commercial oseltamivir suspension can be kept at room temperature for up to 10 days or in the refrigerator for up to 17 days. Oseltamivir suspension prepared by a pharmacist can be kept at room temperature for up to 5 days or in the refrigerator for up to 35 days. Do not freeze oseltamivir suspension. Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
Oseltamivir will not stop you from giving the flu to others. You should wash your hands frequently, and avoid practices such as sharing cups and utensils that can spread the virus to others.
Do not let anyone else take your medication. Your prescription is probably not refillable. If you still have symptoms of the flu after you finish taking oseltamivir, call your doctor.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Last Revised - 01/15/2013
AHFS® Consumer Medication Information. © Copyright, 2015. The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.