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Oseltamivir phosphate oral

Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.





This medication is used to treat illness (symptoms) caused by the flu virus (influenza). Oseltamivir is also used to prevent the flu (e.g., in household members exposed to a flu sufferer).

How To Use

Take this medication by mouth as directed by your doctor. You may take this with food or milk to minimize stomach upset. Take it as soon as flu symptoms appear or as soon as possible after you have been exposed (both within 48 hours). If you have the flu: Take oseltamivir twice a day for 5 days; once in the morning and once in the evening. Complete the entire treatment of 10 doses. To prevent the flu: Take oseltamivir once a day for at least 7 days or take it exactly as prescribed by your doctor. This medication works best when the amount of medicine in your body is kept at a constant level. Therefore, take this drug at the same time(s) each day. Take this medication until the full prescribed amount is finished, even if symptoms improve. Stopping the medication too early may result in a relapse of the infection. Inform your doctor if your condition worsens or if new symptoms appear.

Side Effects

Nausea may occur. If this effect persists or worsens, notify your doctor promptly. Tell your doctor immediately if you have any of these unlikely but serious side effects: dizziness, persistent cough. Tell your doctor immediately if you have any of these very unlikely but serious side effects: persistent weakness, fever, sore throat. If you notice other effects not listed above, contact your doctor or pharmacist.


Tell your doctor your medical history, including: allergies, kidney problems. This drug may make you dizzy or drowsy; use caution engaging in activities requiring alertness such as driving or using machinery. Limit alcoholic beverages. This medication should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor. It is not known if this drug passes into breast milk. Consult your doctor before breast-feeding.

Drug Interactions

Tell your doctor of all prescription and nonprescription medication you may use. Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately.


Do not share this medication with others. Consult your doctor about the risks and important benefits of receiving a yearly flu shot (vaccination) to prevent infection.

Missed Dose

If you miss a dose, use it as soon as you remember. If it is near the time of the next dose (within two hours), skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.


Store at room temperature between 59 and 86 degrees F (15 to 30 degrees C) away from light and moisture.