Re: bioavailability (medical)

[Cathy Quinones <quinones -at- MINDSPRING -dot- COM>]

On Fri, 26 Jan 1996 20:24:24 +0900 Brad wrote:

>I recently came across the word "bioavailable" in some pharmaceutical
>material I was reviewing. Is this a currently popular synonym for
>"efficacy," or does "bioavailable" denote something more, e.g. the speed at
>which the drug is metabolized, takes effect, etc.?

>Context sentence: [drug name] is a more bioavailable form of [chemical
>formulation], and achieves systemic exposure previously attainable only
>with I.V. [drug name]

Yes, they are fairly synonymous, except that bioavailability stresses
whether the compound is at all *available* to the organism in
question.  Efficacy refers to how well something does the job, period;
bioavailability puts the stress on the organism and its ability to use
the compound.  In the context of the sentence above, it means that the
drug, although chemically similar/identical to others, is better
absorbed because of _blank_ (carrying medium, stereochemistry...
whatever).  Bioavailability is simply a more specific term in this
context: if the drug works in test subject #1, but doesn't in test
subject #2, the head honchos will need to change the drug, because
it's unlikely they will be able to force test subject #2 to use what
they've got in the test tube!  I'd say that bioavailability and
availability are synonymous, though.

Cathy Quinones
quinones -at- mindspring -dot- com
http://www.mindspring.com/~mintz/coverpg.html
(that's my web page with pet bird care info)