Tamiflu is an anti-viral medication that can be used to prevent and treat influenza type A and influenza type B. It was also recommended as a treatment during the 2009 swine flu pandemic, now more correctly known as H1N1 flu. Tamiflu is a prescription-only medication, and should only be used if you have had a medical consultation with a doctor and have been issued with a prescription.
Tamiflu works by preventing the spread of the flu virus in your body. Just like with any other anti-viral treatment, it's best to take it as soon as possible after an infection or for prophylaxis to ensure that you get the best benefit. This is because it will be able to inhibit the spread of the virus before it has had a chance to spread, as is demonstrated in the below illustration. Tamiflu is a neuraminidase inhibitor and therefore works to prevent neuraminidase from helping viral cells penetrate new cells so that they can multiply.
Due to the way Tamiflu works, it is at its most effective if taken before the infection has had time to spread. Within 48 hours of experiencing symptoms, you still have enough time to fight off the infection, and stop it from spreading enough to make you very ill.
Similarly, if you come into contact with someone who has the flu and seek medical treatment immediately, you may be able to prevent it from spreading. If you are around people that have influenza, contact a doctor and give them all the information you can. It could be early enough to stop the onset of the virus.
After 48 hours of experiencing flu like symptoms, if you have influenza, Tamiflu usage will not be effective. The reason for this is that the virus will have already infected too many cells in the body. Before experiencing symptoms, it could have already been actively infecting cells for almost two days. By the time you have had symptoms for 48 hours, your body may have been under attack for almost four days. Flu only has about a week before your immune system fights it off in full, so Tamiflu may no longer be useful in cutting down recovery time. You would be advised to use over-the-counter treatments to help you with the symptoms instead.
While Tamiflu is a widely known effective anti-viral medication, it has more recently been suggested for use in people who are at risk of developing complications when infected with influenza. This was a recommendation by the World Health Organisation after the swine flu pandemic was announced in 2009.
People who are at risk of developing more serious conditions when infected with flu and are therefore recommended Tamiflu are people over 65, those with lung disease, long-term kidney disease, heart and neurological diseases and those who don't have a healthy immune system.