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:
- 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.
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:
- 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.