How Effect Will Tamiflu Be? (not very)
Some people are hoping that tamiflu will help halt Asian Flu as/if it starts sweeping across the globe. Do not be optimistic. My friend who is a semi-retired physician has written:
As you know, the only dimly lit corner of the room for efficacy of Tamiflu to save lives in a pandemic comes from the mouse study. In that study, up to 80% of the infected mice survived, if given eight days of treatment instead of the usual five. Only 50% of the latter group survived (or, you may prefer to say, fully half of the mice in this group survived). Those who have taken heart from this study have largely chosen to ignore the fact that the mice were given Tamiflu BEFORE being infected - a difficult act to follow for people in a pandemic. Now it seems there is WORSE news: while the suggestion was that higher than currently recommended doses would be more efficacious , an astute reader has uncovered the fact that the mice on the highest study dose were, in fact, given FIVE TIMES the currently recommended dose. The real expected mortality rate taking the recommended dose, even while starting before infection, would be quite abysmal, if results were directly transferable to humans.For more on Avian Flu, along with many up-to-date items and links, be sure to bookmark this blog.
The actual study, which I haven't been able to get yet, is:
Reference: H. Yen et al. Virulence may determine the necessary
duration and dosage of oseltamivir treatment for highly pathogenic
A/Vietnam/1203/04 (H5N1) influenza virus in mice.
Journal of Infectious Diseases DOI:10.1086/432008 (2005).
Here is the thread on the dosage bombshell:
Re:Mouse Studies of Oseltamivir Show Promise Against H5N1 Influenza Virus
« Reply #20 on: August 08, 2005, 04:31:26 am »
Quote from: hydra on August 07, 2005, 11:36:31 pm
Either I am crazy or the NIH is making a mistake. The highest dose used in this study is 10mg/kg/day. For a 75kg human male, that would mean taking 750mg/day of oseltamivir.
Now, I have a box of tamiflu sitting right in front of me. There are 10 capsules, each capsule contains 75mg, and the dosing instructions are take 1 capsule twice a day. The total dose per day is therefore 150/mg/day, NOT 750mg/day.
Therefore, this statement in the NIH article above "The highest dosage level, adjusted for weight, was equivalent to the dose currently recommended for humans sick with the flu. "
In fact, the recommended dose of human 2 capsules a day is about 2mg/kg/day, or about 1/5 the highest dose in this study.
Please correct me if I'm wrong.