What is this medication for?

Oseltamivir is used to prevent or treat infections caused by influenza viruses (Type A and B). It is an antiviral medication that works by preventing the release of influenza viruses from infected cells, thereby preventing new rounds of infection.

Oseltamivir is not a substitute for influenza vaccination.

How should I take or use this medication?

• Do not stop taking your medication without checking with your healthcare professional.
• You may take Oseltamivir with or without food.
• The capsules may be opened to provide the correct dosage when given for a child or for those who cannot swallow. As powder from the capsules can be irritating to the skin and eyes, open the capsules with care. If powder comes in contact with eyes or skin, rinse with plenty of water immediately.

For patients who cannot swallow the capsules:

• Carefully open one capsule and pour all the powder into a plastic cup.
• Add 10mL of water to the plastic cup and mix for 2 minutes.
• Use the syringe to measure out the prescribed volume and discard the remaining mixture.
• Add the mixture measured out to a small volume of one of the following sweetened liquids listed below and serve to your child.
• For doses which are the full dose of the capsule: If there is some mixture left in the plastic cup, rinse the cup with a small amount of water and drink it all.

As Oseltamivir is very bitter and the taste can be masked by mixing the contents of the capsule(s) with sweetened liquids as indicated below:

The following sweetened liquids are:

• Ovaltine*
• Milo*
• Rose syrup
• Maple syrup
• Cherry syrup
• Condensed milk
• Chocolate syrup (Nestle’s or Hershey’s)
• Nestle’s Nesquik Plus + 50% water*
• Melted Vanilla and Chocolate Ice Cream
• Honey (for children ≥2 years of age)

* Allow these drinks to cool to room temperature before medication is added.

What should I do if I forget to take or use this medication?

If you forget to take a dose, take it as soon as you remember. Then take your next dose at the usual time. Do not take two doses to make up for the missed dose.

What precautions should I take when taking or using this medication?

Inform your healthcare professional if: 

• You are allergic to this medication or any of the other ingredients of this medication
• You are pregnant, planning to become pregnant, or breastfeeding.
  • Pregnancy: Pregnant women might be at a higher risk of severe complications from influenza. Although there are limited studies in pregnant women and insufficient clinical experience to confirm its safety in pregnancy, the benefits of treatment or prophylaxis is likely to outweigh the theoretical risks of antiviral use, individuals prescribed with Oseltamivir are highly encouraged to comply with treatment.
  • Breastfeeding: Breastfeeding while taking Oseltamivir can be continued. Breastfeeding provides antibodies to the infant which makes them less vulnerable. Whenever possible, breastfeed the infant or express breast milk before taking Oseltamivir to minimize the infant’s exposure.
• You are taking any other medications, including supplements, traditional medications and herbal remedies. 

What are some common side effects of this medication?

• You may experience nausea, vomiting or diarrhea
  • For nausea and vomiting, take the medication after food. Also, you may take small frequent meals or suck on sweets.
  • For diarrhea, drink more water to ensure sufficient hydration. If diarrhea is severe, stop taking Oseltamivir and speak with your doctor about it.
• You may experience dizziness.
  • Get up slowly from a sitting or lying position.
• You may experience headache.
  • Have plenty of rest and take painkillers if necessary.

What are some rare but serious side-effects that I need to seek medical advice immediately?

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

Neuropsychiatric reactions such as:

• Confusion
• Delirium
• Hallucinations or unusual thoughts or behavior 

Symptoms of a drug allergy which includes one or more of the following:

• Swollen face/eyes/lips/tongue
• Difficulty in breathing
• Itchy skin rashes over your whole body

What food or medication should I avoid when I take or use this medication?

Live influenza vaccine should be avoided within 2 weeks before or 48 hours after administration of Oseltamivir unless medically indicated. 

Avoid using Oseltamivir together with Probenecid.

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children. 

How do I throw away this medication safely?

Pack this medication into a black trash bag and seal it tightly before throwing into the rubbish chute or bin.

Disclaimer

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on August 2021