Medications to treat or prevent influenza (“the flu”)
Treatment with oseltamivir (Tamiflu®) or zanamivir (Relenza®) may prevent infection with influenza ("the flu"), or shorten the duration and severity of illness in people that already have influenza.
Last updated: 06 November 2006
Influenza is caused by the influenza virus. The symptoms of influenza usually include the sudden onset of fever and chills, cough, muscle and joint pain, headache, tiredness and weakness. Some people also get a stuffy nose and sore throat. For more information about influenza, see the Influenza fact sheet.
The best way to prevent influenza is to have an annual influenza vaccination. Other things you can do to prevent influenza from spreading include covering your nose and mouth with a tissue when coughing or sneezing and washing your hands with soap and running water after coughing or sneezing. If you are ill with influenza, you should stay at home until you feel better. If you need to go to the doctor, you should wear a mask while in the doctor's waiting room.
The most useful antiviral medications for treating and preventing infection with influenza are the group of drugs called the neuraminidase inhibitors - oseltamivir (trade name: Tamiflu®) and zanamivir (trade name: Relenza®). They can be used to treat and prevent both human influenza ("the flu") and avian influenza ("bird flu").
How do these medications work?
Neuraminidase inhibitors 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?
What is the dosage?
Tamiflu comes as a capsule for adults, and as a suspension for children, which should be taken by mouth. The dosage in adults without severe kidney problems is:
Relenza is inhaled using an inhaler that comes with the pack. Follow the instructions in the pack on how to use the inhaler. The dose in adults and children over 5 years old is:
Who should NOT take these medications?
You should not take Tamiflu or Relenza if you are allergic to these medications, or to any of the medication ingredients. Before starting treatment, tell your doctor about other medications you may be taking. You should also tell your doctor if you have any chronic or serious illnesses, in particular if you have kidney disease, asthma or lung disease, as special precautions may be needed.
What are common side-effects of taking these medications?
Overall, the neuraminidase inhibitors are very safe. The commonest side effects of these medications 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 may help 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.
Can I take other medications at the same time?
Tamiflu and Relenza are generally safe to take with other medications, but you should still make sure that your doctor knows about any other medications you are taking. If you normally use certain asthma inhalers such as salbutamol (e.g., Ventolin), or terbutaline (e.g., Bricanyl), you should use these at least 5 minutes before taking Relenza.
What if I am pregnant or breast-feeding?
If you are pregnant or planning to become pregnant, tell your doctor before taking this medication. Both Tamiflu and Relenza are relatively new medications, and their safety during pregnancy or breast-feeding is not completely understood. They should therefore be avoided if possible during pregnancy or while breast-feeding, unless the risk from getting influenza is thought to outweigh the potential risk of these medications to the baby.
|Further information - Public Health Units in NSW|
|For more information please contact your doctor, local public health unit or community health centre - look under NSW Government at the front of the White Pages|
|Metropolitan Areas||Location||Number||Rural Areas||Location||Number|
|Northern Sydney||Hornsby||02 9477 9400||Greater Southern||Goulburn||02 4824 1837|
|Central Coast||Gosford||02 4349 4845||Albury||02 6080 8900|
|South Eastern Sydney||Randwick||02 9382 8333||Greater Western||Broken Hill||08 8080 1499|
|Illawarra Shoalhaven||Wollongong||02 4221 6700||Dubbo||02 6841 5569|
|Sydney South West||Camperdown||02 9515 9420||Bathurst||02 6339 5601|
|Sydney West||Penrith||02 4734 2022||Hunter/New England||Newcastle||02 4924 6477|
|Parramatta||02 9840 3603||Tamworth||02 6764 8000|
|Justice Health Service||Matraville||02 9311 2707||North Coast||Port Macquarie||02 6588 2750|
|Lismore||02 6620 7585|