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.
If you are giving the commercial suspension to an adult or child over one year of age, follow these steps to measure the dose using the syringe provided:
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.
If you have difficulty swallowing capsules, your doctor may tell you to open the capsule and mix the contents with a sweetened liquid. To prepare doses of oseltamivir for people who cannot swallow the capsules:
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.
Before taking oseltamivir,
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.
Oseltamivir may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
Some side effects can be serious. If you experience any of these symptoms or those mentioned in the SPECIAL PRECAUTIONS section, call your doctor immediately:
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 ( Web Site ) 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.
It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. Web Site
Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website ( Web Site) for more information if you do not have access to a take-back program.
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at Web Site. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
Symptoms of overdose may include:
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.
AHFS® Consumer Medication Information. © Copyright, 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.
Selected Revisions: January 15, 2018.