Generic Oseltamivir

Common use

Oseltamivir suppresses and decreases the spread of influenza A and B viruses. It blocks activity of neuraminidase, the enzyme, which is responsible for the spreading of the flu virus from infected cells to healthy ones. Blocking of the virus propagation stops production of toxins which are responsible for severe symptoms of flu. Oseltamivir reduces the duration of symptoms by one and a half days if treatment is started within forty-eight hours of the beginning of symptoms. It may also be given as a prophylactic drug to prevent influenza in people who have contacted the sick but still have not had symptoms.





Dosage and direction

Take Oseltamivir orally by 75 mg twice daily for five days. Prophylactic dose in people after close contact with the sick is 75 mg daily for 10 days. Dosage for children should be corrected according to their weight.



Precautions

Treatment with Oseltamivir should be started as soon as symptoms of flu appear. Do not stop treatment even if your symptoms improved as the infection may not be completely treated. Inform your doctor before to take Oseltamivir if you have kidney disease, heart disease, lung disease, a condition causing swelling or disorder of the brain, any other serious disease or health problem. This medication is recommended for treatment of children one year old and older, in women with flu who have recently given birth. Though vaccines may be harmful to an unborn baby the risk of flu may be even more dangerous, so your doctor should decide whether you should receive this vaccine, especially if you have a high risk of infection with H1N1 influenza.



Contraindications

Hypersensitivity to components of the medication. Dose adjustment is needed either for treatment or prevention in adults with severe renal insufficiency.



Side effects

Rare side effects of Oseltamivir include sudden confusion, delirium, hallucinations, unusual behavior, or self-injury, most frequent ones are nausea, vomiting, diarrhea, bronchitis, abdominal pain, headache and dizziness. Allergic reactions, aggravation of diabetes also have been reported.



Drug interaction

Do not use a nasal flu vaccine (FluMist) within 48 hours after taking Oseltamivir. Inform your doctor about all prescribed and non-prescribed medications and herbal products you are taking including minerals and vitamins.



Missed dose

Take the dose you forgot as soon as possible. If less than two hours remained till your next dose just skip the missed dose and return to your regular schedule.



Overdose

Symptoms of overdose include nausea and vomiting. If you suppose that took too much of the medication seek for immediate medical help.



Storage

Store at room temperature between 20-25 C (68-77 F).



Disclaimer

We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions. Information at the site cannot be used for self-treatment and self-diagnosis. Any specific instructions for a particular patient should be agreed with your health care adviser or doctor in charge of the case. We disclaim reliability of this information and mistakes it could contain. We are not responsible for any direct, indirect, special or other indirect damage as a result of any use of the information on this site and also for consequences of self-treatment.

Clinical Verification

Last Clinically Updated: August 15, 2026

Written By

Dr. Elena Vance, PharmD

Clinical Specialist in Neuropharmacology

Fact Checked By

Marcus Thorne, MS

Biomedical Data & FDA Label Verification

Medically Reviewed By

Dr. Arthur Campbell, MD

Board-Certified Psychiatrist (ABPN)