More info on Propecia and Proscar.  They both contain the active ingredient
finasteride.  (Propecia has 1 mg and Proscar has 5 mg.) Why does a prostate
become enlarged?
 
In the prostate testosterone is converted to dihydrotestosterone (DHT).
DHT is the major androgen of the prostate.  DHT is the key hormone
stimulating the enlargement of the prostate (both in the stromal and
glandular compartments).  Estradiol, testosterone, and other growth factors
are also involved.  Propecia/Proscar blocks the enzyme that converts
testosterone into DHT.  This lowers the DHT level in the serum and in the
prostate and causes the prostate to decrease in size.  DHT also effects
the liver and causes hair lose (male pattern baldness).  That is why
Propecia is marketed for hair loss in humans, while Proscar is marketed
for prostatic hyperplasia in humans (BPH).
 
There is a good article about using Propecia/Proscar in dogs for prostatic
enlargement in JAVMA April 15, 2001.
 
Again I use it with Lupron.  Lupron to control the adrenal gland hormones
and Propecia to control DHT and the prostate.
 
I hope that answers your questions,
Jerry Murray, DVM
[Posted in FML issue 3410]