Tamiflu (Oseltamivir) For Flu

Active ingredient: Oseltamivir phosphate
Class: Antiviral, Neuraminidase Inhibitors
Manufacturer: Hoffmann La Roche Inc.

Tamiflu (Oseltamivir phosphate) is an antiviral medicine effective against influenza types A and B. When started during the first 2 days of the illness, Oseltamivir speeds recovery and reduces the duration of flu by 1.5 days.

Tamiflu is also used for the prevention of influenza. It can prevent the flu as long as you continue taking the medicine.

How effective is Tamiflu?

According to a major review of over 50 studies published in 2006, Tamiflu is effective against the flu in about 60% of cases.

Oseltamivir phosphate is active against both influenza types A and B. It can reduce the severity and duration of illness or help to reduce the chance of getting the flu. The sooner Tamiflu is started after symptoms onset, the more effectively it works.

As the flu virus penetrates into the body, it forms new copies of itself and spreads from cell to cell. Tamiflu fights the virus by preventing the release of new copies from infected cells. Oseltamivir works by blocking a key viral enzyme, neuraminidase, which is involved with viral replication.

Tamiflu may not prevent the development of immunity. When used as prophylaxis, oseltamivir can prevent illness while permitting sub-clinical influenza and development of protective antibody against circulating viruses.

What are the disadvantages?

About 10 - 15% of persons experience nausea and vomiting. These side effects are usually subsided when oseltamivir is taken with food.
There is no such thing as generic Tamiflu. Being available exclusively as brand made by Hoffman La Roche it is pretty expensive.
Limited production capacity. The manufacturing process for oseltamivir is complex and time-consuming, involving a complex, 10-step process that takes approximately 6-8 months.
To be effective as much as possible for flu prevention, oseltamivir must be taken each day during the influenza epidemic, not just the peak period. This makes use of Tamiflu as prophylaxis questionable and potentially very expensive.
Timing is very critical. The treatment should be started within 2 days of the start of flu symptoms to be effective.
Benefits may be limited when used as treatment - oseltamivir can reduce the duration of uncomplicated influenza by approximately one day. The effectiveness in preventing serious influenza complications is unclear.

Dosage

Treatment of Influenza: The usual dosage is 75 mg taken twice daily (morning and evening) for 5 days. If you have kidney disease, take a 75 mg dose once a day.

Prevention of Influenza: The usual dosage is 75 mg taken once a day for at least 7 days. If there is a flu epidemic, your doctor may recommend that you continue taking Tamiflu for up to 6 weeks. If you have kidney disease, take a 75 mg capsule every other day, or 30 mg of liquid once a day.

For children 1 to 12 year old the dose is determined by a pediatrician according to the child's weight. Tamiflu should not be used to treat the flu in children under 1 year old.