Tamiflu® and Relenza®

Treatment with the anti-influenza medications oseltamivir (Tamiflu®) or zanamivir (Relenza®) may shorten the duration and severity of illness in people that already have influenza. This year, people at highest risk of complications from influenza are being encouraged to seek early medical attention, so that they can receive treatment with these medications, if appropriate. Medications are available through a private prescription from their medical practitioner.

You should read this advice in conjunction with the product information provided by the manufacturer.

How do these medications work?

Oseltamivir (Tamiflu®) and zanamivir (Relenza®) are from a drug group called neuraminidase inhibitors. They prevent the influenza virus from spreading inside your body. If started within 48 hours of the first symptoms of influenza, these medications can reduce the severity of symptoms, and can reduce the time taken to recover from illness.

What are these medications used for?

Oseltamivir (Tamiflu®) can be used for treating people aged 12 months or older, who are infected with Pandemic (H1N1) 2009 influenza. Zanamivir (Relenza®) can be used in those 5 years or older. These medications are most effective if they are started within 48 hours (2 days) of starting to feel unwell. The earlier they are started after the onset of symptoms, the more effective they are. In certain cases where there is severe illness requiring hospitalisation treatment may be considered after this time.

How is the medication taken?

Oseltamivir (Tamiflu®) comes as a capsule for adults, and as a suspension for children, which should be taken by mouth. Your doctor will advise you on dosage, which depends on your age, health status and whether you have symptoms of influenza.

Zanamivir (Relenza®) is inhaled using an inhaler that comes with the pack. Follow the instructions in the pack on how to use the inhaler or ask your doctor or pharmacist. Your doctor will advise you on dosage, which depends on your age, health status and whether you have symptoms of influenza or are contact of a person with influenza and are at very high risk of complications.

Who should not take these medications?

Overall, these medications are very safe. The most common side effects are nausea, vomiting and other gastrointestinal symptoms. These affect less than 1 in 10 people, most often the first time the medication is taken. Taking the medication with food often helps to reduce or prevent these side effects. If you notice any other side effects or if you have any concerns about possible side effects, please talk to your doctor.

Use of oseltamivir for young children

In very young children (those under 12 months) oseltamivir (Tamiflu®) should be given under the advice of a paediatrician.

What if I am pregnant or breast-feeding?

If you are pregnant or planning to become pregnant, tell the person prescribing you the medication before starting the course of medication. The benefits and risks of these medications should be discussed with your health care provider.​

Page Updated: Thursday 12 May 2016
Contact page owner: Communicable Diseases