Floriano wrote:
>
>Can you elucidate me some as to how these drugs did get the OK in the >first
>place if the prio proven results were completely documented?
>
Dear Floriano,
Assuming that a regulatory agency is functioning optimally and responsibly, two
reasons why a drug that got an approval initially might be withdrawn
subsequently are as follows:
1. Detection of a rare adverse effect that was not caught in the clinical
trials e.g. a one in 1000,000 chance of dying might not be caught in a
scientific study involving 10,000 patients, and a study involving millions of
patients would not be feasible.
2. Detection of an adverse effect that occurs only after decades long treatment
with the drug e.g. a troublesome side effect that appears only after 30 years
of being on the same drug, which could not be known when the drug was first
introduced.
In cases where these things occur, it is the withdrawal that is invariably the
politically expedient action because it is extremely difficult to prove that a
rare event is caused by the drug. Barring the possibility of outright fraud,
there is usually nothing unscientific about the initial approval.
Cheers,
Santosh
