Re: bicalutamide a castration drug? [1 Attachment]

[Guest guest]

Chuck Maack wrote:

> Attached is an explanation of the role of LHRH agonists, GnRH

> antagonists, antiandrogens, and 5Alpha Reductase (5AR)

> inhibitors in androgen deprivation therapy (ADT)....

That was a very lucid explanation Chuck. Thank you.

Here's another article I found on the web about Casodex:

http://www.drugs.com/pro/bicalutamide.html

You can also get the actual FDA drug " label " for the drug from

the National Library of Medicine here:

http://dailymed.nlm.nih.gov/dailymed/about.cfm

Type " bicalutamide " in the search box.

's explanation of how it works is the right idea but I'd

like to elaborate a bit. The drug doesn't bind to testosterone,

it binds to the testosterone receptors on the surfaces of cells -

which accomplishes the same thing.

You can think of hormones as being like little keys that float in

the blood stream and receptors as being like little locks on the

surfaces of cells. Any particular lock only accepts one kind of

key. When the key is inserted, the lock opens up a chain of

chemical reactions inside the cell or, in this case, passes the

key inside where it starts a chain of chemical reactions.

There are several ways to block the action of a hormone. You can

stop production of the hormone. That's what Lupron does, for the

major source of testosterone - the testicles. You can bind

something to the key so it no longer fits the lock. Or you can

gum up the lock by sticking something in it that is not the

hormone but makes it impossible for the hormone to get in.

That's what Casodex/bicalutamide does. Avodart and Proscar do

something very similar but they gum up locks inside the cell,

stopping reactions of any testosterone molecules that made it

past the Lupron or the Casodex.

According to the first article I cited above, Casodex can

actually cause the body to create extra testosterone. That isn't

too surprising because the body is " homeostatic " , meaning that it

has various mechanisms that compensate for disturbances to try to

return everything to a standard state, much the way a thermostat

turns on the heat if it gets too cold in a house or turns it off

if it gets too hot. That's one reason why Casodex is now usually

used in conjunction with Lupron or similar drugs.

Actual castration, i.e., surgical removal of the testicles, is

most like Lupron. It removes the major testosterone producer in

the body.

Alan