What half-life means

November 12, 2006 at 1:02 am

I have noticed that the term half-life is occasionally misunderstood. I hope I can clarify it. In the case of IVIg, the half-life is 21 days, according to one of the doctors at the Symposium (I did not note who, sorry). That means at 21 days, half of the original load of antibodies is left. At 42 days, one-quarter of the original load is left (half of the load at 21 days). At 63 days, one-eighth of the original load remains, and so on.

If I use IVIg, I need 0.5 g per kilogram of body weight once a week, and I still need an immunosuppressant. I agree with the others that you should try to get treatment more often, because by the end of the three months, you have very little of the initial load left. It seems to be a fairly rare person who can get IVIg once a quarter and do well. Godspeed in this.