Lupron is one of a class of drugs called GnRH agonists
- they act on the brain to stimulate
the production of testosterone by the testicles. The surge of testosterone causes a negative feedback loop whereby the brain then shuts down the testicular production of testosterone completely. Another drug, called Firmagon is a GnRH antagonist
- it directly shuts down testosterone production, without a negative feedback. They both accomplish the same thing, and get rid of the bulk
of the testosterone your body produces.
But there are much smaller amounts of testosterone that may be produced within the adrenal glands and in the tumor itself. Zytiga inhibits enzymes that are responsible for those sources of testosterone. So Zytiga is never used instead of a GnRH agonist or antagonist, but is only used complementary to their use.
A third kind of drug, anti-androgens, like bicalutamide (Casodex) or enzalutamide (Xtandi), work in a different way. They block the androgen receptor on cancer cells so that testosterone can no longer activate it. Without activation, the cancer cell cannot multiply.
Allen - not an MD
•PSA=7.3, prostate volume=55cc, 8/17 cores G6 5-35% involvement
•SBRT 9 yr onc. results
•SBRT 7 yr QOL results
•treated 10/2010 at age 57 at UCLA,PSA now: 0.1,no lasting urinary, rectal or sexual SEsmy PC blog