OSELTAMIVIR (os el TAM i vir) prevents and treats infections caused by the flu virus (influenza). It works by slowing the spread of the flu virus in your body and reducing how long your symptoms last. It will not treat colds or infections caused by bacteria or other viruses. It will not replace the annual flu vaccine.
What should I tell my care team before I take this medication?
They need to know if you have any of the following conditions:
Difficulty swallowing
Kidney disease
An unusual or allergic reaction to oseltamivir, other medications, foods, dyes, or preservatives
Pregnant or trying to get pregnant
Breast-feeding
How should I use this medication?
Take this medication by mouth with water. Take it as directed on the prescription label at the same time every day. You can take it with or without food. If it upsets your stomach, take it with food. Take all of this medication unless your care team tells you to stop it early. Keep taking it even if you think you are better.
When taking whole capsules: Do not cut, crush, or chew this medication. Swallow the capsules whole.
When mixing capsule contents with liquid: Open the capsule and mix the contents in a small bowl with a small amount of a sweetened liquid such as chocolate syrup, corn syrup, caramel topping, or light brown sugar (dissolved in water). Stir the mixture and take the dose right away after mixing.
Talk to your care team about the use of this medication in children. While it may be prescribed for selected conditions, precautions do apply.
What if I miss a dose?
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose (within 2 hours), take only that dose. Do not take double or extra doses.
What may interact with this medication?
Intranasal influenza vaccine
What side effects may I notice from receiving this medication?
Side effects that you should report to your care team as soon as possible:
Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
Confusion
Hallucinations
Redness, blistering, peeling, or loosening of the skin, including inside the mouth
Seizures
Tremors or shaking
Trouble speaking
Unusual changes in behavior
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
Headache
Nausea
Vomiting
What should I watch for while using this medication?
Visit your care team for regular checks on your progress. Tell your care team if your symptoms do not start to get better or if they get worse.
If you have the flu, you may be at an increased risk of developing seizures, confusion, or abnormal behavior. This occurs early in the illness, and more frequently in children and teens. These events are not common, but may result in accidental injury to the patient. Families and caregivers of patients should watch for signs of unusual behavior and contact a care team right away if the patient shows signs of unusual behavior.
To treat the flu, start taking this medication within 2 days of getting flu symptoms.
This medication is not a substitute for the flu shot. Talk to your care team each year about an annual flu shot.
Where should I keep my medication?
Keep out of the reach of children and pets.
Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Throw away any unused medication after the expiration date.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.
This information is educational only and should not be construed as specific instructions for individual patients nor as a substitute for medical advice, diagnosis or treatment. Talk to your health care provider or pharmacist about the information and instructions. K Health assumes no liability for any use or reliance on this information.
