Oseltamivir

Sounds like 'oss-el-TAM-eh-veer'. Also known as Tamiflu®

Easy-to-read medicine information about oseltamivir – what is it, how to take oseltamivir safely and possible side effects.

Type of medicineAlso called
  • Belongs to a group of medicines called anti-viral medicines 
  • Tamiflu®

What is oseltamivir?

  • Oseltamivir is used to treat and prevent symptoms caused by the influenza (flu) virus. 
  • It works by attacking the influenza virus and stopping it from multiplying in your body. 
  • Oseltamivir is available as capsules or a liquid suspension.
  • In New Zealand, oseltamivir is not funded by the government, which means the patient has to meet the full cost. It is not free on prescription. 
To treat influenza
  • If you already have signs and symptoms of the flu, oseltamivir helps to reduce symptoms such as fever, chills, stuffy nose, cough, sore throat, aches, and tiredness. It shortens the time to recover from the flu by 12 to 24 hours.
  • Oseltamivir can reduce the chance of illnesses that may occur as a result of the flu (called complications) such as pneumonia. People at higher risk of complications include:
    • pregnant women
    • older adults aged > 65 years
    • people with chronic disease or respiratory condition such as asthma.
  • Oseltamivir is most effective when it is started within an hour or two of the first symptoms of the flu, but it can still be effective after this time, as long as it is started within 48 hours of the first symptoms.
To prevent influenza
  • Oseltamivir may also be used to prevent the flu if you have been exposed to someone who already has the flu (such as a sick household member) or if there is a flu outbreak in the community.
  • To prevent influenza, oseltamivir is most effective when it is started within 2 days of exposure.
  • Oseltamivir is not a substitute for the flu vaccine. Getting the flu vaccine is the best way to protect against getting the flu and to control the spread of the flu.

Dose

  • The dose of oseltamivir is different depending on whether it is used to treat influenza or prevent influenza.
  • To treat influenza:
    • The usual dose of oseltamivir is 75 milligrams every 12 hours for 5 days.
    • Oseltamivir is most effective when it is started within an hour or two of the first symptoms of the flu, but it can still be effective after this time, as long as it is started within 48 hours of the first symptoms.
  • To prevent influenza:
    • The usual dose of oseltamivir is 75 milligrams once daily for 10 days.
    • In some cases oseltamivir can be continued for up to 6 weeks during an influenza epidemic.
  • Always take your oseltamivir exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much oseltamivir to take, how often to take it, and any special instructions.

How to take oseltamivir

  • Swallow your oseltamivir capsules with a glass of water.
  • You can take your oseltamivir capsules with or without food. You may take it with food or milk to reduce stomach upset.
  • If you are taking oseltamivir twice a day, space your doses evenly throughout the day. So, for example, take one dose in the morning and the other in the evening
  • If you forget your dose, take it as soon as you remember that day. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the dose.
  • Continue to take oseltamivir for the full time it has been prescribed. Stopping the medication too early may result in a return of the infection or failure to protect you from the flu.

Possible side effects

Like all medicines, oseltamivir can cause unwanted side effects, although not everyone gets them. Often unwanted side effects improve as your body gets used to the new medicine.

Side effectsWhat should I do?
  • Nausea (feeling sick) and vomiting (throwing up) 
  • Tummy (abdominal) pain
  • These are quite common when you first start taking oseltamivir and usually settle within 2 days
  • Try taking oseltamivir with food 
  • Tell your doctor if troublesome
  • Headache
  • Feeling tired
  • Tell your doctor if troublesome
  • Signs of an allergic reaction such as skin rash, itching, swelling of the lips, face, and mouth or difficulty breathing
  • Tell your doctor immediately or ring HealthLine 0800 611 116

Learn more

Tamiflu® Medsafe Consumer Information Sheet

 

Credits: Sandra Ponen, Pharmacist.