Tamiflu (Oseltamivir Phosphate) for H1N1 Swine Flu, Avian Flu, Influenza A & B

Introduction

The American FDA has approved Tamiflu an oral anti-viral drug for the treatment of uncomplicated influenza in patients one year and older whose flu symptoms have not lasted more than two days. Tamiflu (Oseltamivir phosphate) was developed by US-based Gilead Sciences and is currently marketed by Hoffmann-La Roche (Roche) under the trade name Tamiflu.

Main Item

Tamiflu is an antiviral drug that is used in the treatment and prophylaxis of both Influenza virus A and Influenza virus B infection. Like zanamivir, Tamiflu is a neuraminidase inhibitor. It acts as a transition-state analogue inhibitor of influenza neuraminidase, preventing progeny virions from emerging from infected cells.

With increasing fears about the potential for a new swine flu pandemic, Tamiflu has received substantial media attention. Governments, corporations, and even some private individuals are stockpiling the drug. Production is currently sufficient to meet the demand only for seasonal influenza and for government stockpiling. It is possible that shortages will recur in the event of an actual swine influenza pandemic.

Oseltamivir was widely used during the H5N1 avian influenza epidemic in Southeast Asia in 2005. In response to the epidemic, various governments - including those of the United Kingdom, Canada, United States and Australia - stockpiled quantities of oseltamivir in preparation for a possible pandemic. Though large, the quantities stockpiled would not have been sufficient to protect the entire population of these countries. It is possible that shortages could again be encountered if a global swine flu pandemic actually arises.

Quick Facts on Tamiflu

• Tamiflu should be started as soon as possible after a child develops flu symptoms, and at least within two days, or as soon as possible after you have been exposed to someone with the flu, if you have not had a flu shot.
• The trade name for Tamiflu is oseltamivir phosphate.
• Tamiflu is a neuraminidase inhibitor.
• Tamiflu is effective against both type A and B strains of flu.
• There is no generic version of Tamiflu available.
• 10 capsules (minimum amount) can cost over $80.
• Tamiflu helps to reduce your time with flu symptoms by about 1.3 days.

Dosage of Tamiflu

Oseltamivir is marketed by Roche under the trade name Tamiflu, as capsules (containing oseltamivir phosphate 98.5 mg equivalent to oseltamivir 75 mg) and as a powder for oral suspension (oseltamivir phosphate equivalent to oseltamivir 12 mg/mL).

For Treatment of Flu

Adults and teens over 13 take 75mg Twice a day for 5 days. The dosage for younger children who are 1 year and older depends on their weight:

• + < 33lbs - 30mg - need 1 bottle
• + > 33 to 51lbs - 45mg - need 2 bottles
• + > 51 to 88lbs - 60mg - need 2 bottles
• + > 88lbs - 75mg - need 3 bottles

For Prevention of Flu

• Adults and teens take 75mg once a day for 10 days
• Children over 1 year old take the same dose they would for treatment of the flu, but take it just once a day for 10 days

Side Effects

The most common side effects of Tamiflu are nausea, vomiting, diarrhea, and conjunctivitis (pinkeye). Sometimes people report getting headaches after taking Tamiflu. There are concerns that oseltamivir may cause dangerous psychological, neuropsychiatric side effects including self harm in some users. These dangerous side effects occur more commonly in children than in adults.