From:
"Mike Janke"
Date: 2004-05-02 02:14:29 UTC
Subject: 24 hour Lupron usage
To: <ferrethealth@smartgroups.com>
Message-Id: <E1BK6Ur-0004vb-00@avocet.mail.pas.earthlink.net>
A while back, someone wrote to me asking questions about Lupron. Several
emails were exchanged and this led to my learning that a pharmacy and
vet in the Midwest is selling 24 hr. Lupron across the U.S. with the
claim that it is effective for approximately one month. I was surprised
to hear this and didn't believe this to be true, but since I'm not a vet
or medical expert, I told this person that I would do some research
before making any claims.
I tried to get a better explanation from the vet and pharmacist
prescribing this Lupron, to no avail. In their defense, I did not speak
to them directly but through a second party. The only thing I knew was
the claim that it worked long term because of, "the way it attaches to
the adrenal receptors." I was looking for a little more detailed
explanation how this works for a period longer than 24 hours but never
found out any more than that.
I wrote to several vets I know and whose names would probably be
familiar to many here and the response I got was that 24 hr. Lupron
works for 24 hrs., period. That was appreciated but their response did
not include any real explanation as to why it could not work as claimed.
I then decided to contact John Hines, who wrote, "Adrenal Disease and
the Therapeutic Effect of Lupron." Since John studied the topic of
Lupron usage and has a Ph.D. in Pharmacology, I felt I wouldn't find
anyone more knowledgeable on the subject and definitely one with the
credentials to offer an expert opinion.
First a brief layman's description (mine!) of how Lupron works so some
of John's comments might make a little more sense. Lupron desensitizes
the pituitary gland and causes it to stop producing two hormones, LH and
FSH. These two hormones (the primary problem is LH I believe) stimulate
the adrenal glands into producing sex hormones which cause the adrenal
disease symptoms we see. This is an extremely basic explanation. There
are many more details in John's paper and if you'd like to read his
paper and get a little more scientific explanation, go to
http://www.miamiferret.org/fhc/lupron.htm.
The main question to John was, how can 24 hr. Lupron be effective in
ferrets for adrenal disease treatment if used as a monthly dose? John's
comments on the topic were as follows...
[all quoted material posted with John's permission]
"... if the Lupron is of the type that all enters the bloodstream in 24
hrs., (24 hr. Lupron) what you get is a few hours of high pituitary
activity followed by only several HOURS of inactivity (desensitized).
Then the 24 hr. Lupron is gone shortly thereafter, and the pituitary
RE-sensitizes and LH release to the natural GnRH resumes probably in a
day or so. If the ferret is only getting the 24hr. shot once a month,
it's useless. In fact, the use of the 24 hr. Lupron probably makes the
adrenal disease worse because you don't get much therapeutic effect, but
you are still getting that initial high pituitary activity when the
Lupron is first administered. This initial burst of pituitary activity
is of little consequence when it is followed by cessation of pituitary
activity. But, with the 24 hr. Lupron, you get only the initial burst
of pituitary high activity -- followed by normal pituitary activity.
It's like adding a splash of gasoline to a fire."
We had several discussions, particularly about the claim that the 24 hr.
Lupron works for a month or more because of "the way it attaches to the
adrenal receptors" to which John responded...
"I did notice in your earlier correspondence that the vet and pharmacist
had described their Lupron as binding to 'adrenal receptors'. I can
see how a drug that binds to the pituitary and impacts on the adrenals
could be misconstrued as binding to the adrenals by the average person;
however, if the pharmacist or vet actually said to her that "Lupron
binds to adrenals", then that immediately is cause for concern as it
demonstrates a fundamental ignorance about how the drug works."
And...
"[pharmacist's name omitted] doesn't understand how Lupron works. He
seems to know what its ultimate effect is, just not the mechanism.
That's a shame, because he should know better than anyone. Leuprolide
binds to receptors on the pituitary. The word "attach" could be
misleading -- to some people it might imply a permanent joining of the
leuprolide to the GnRH receptor, which is not the case. Leuprolide
tightly associates ("binds") with the GnRH receptor, but it is a
reversible process. It can dissociate ("unbind") as well."
I want to thank John for putting up with all my questions and taking
time out of his busy days to share his knowledge on this topic.
I know that this vet does a lot of good for ferrets and I understand the
intent is to offer an affordable alternative for treatment of this all
too common disease. Does this Lupron work in some cases? So I hear.
What worries me, besides the fact that this type of Lupron may not work,
is that after hearing John's explanation, realizing that there is also
the chance it could make the condition worse.
The other important message I want to get across is, ask questions, know
what you are getting and what you're treating your ferret with. This
applies to ANY treatment, not just one for adrenal disease. In this
case, I was told by the person that contacted me that she was not told
that what she was getting was 24 hr. Lupron, only that it would work for
a month or so. I am fairly sure that if the vet had been asked
directly, "Is this 24 hr. Lupron?" or "What formulation of Lupron is
this?" the vet would have been honest and upfront. Vets (even human
doctors) often don't give us all the information unless we specifically
ask for it. So don't be afraid to ask.
If this 24 hr. Lupron is something you want to try for whatever reason,
this probably won't change your mind. Just be aware that you may see no
results and in fact, may make matters worse.
mike
End of ferrethealth Digest
***********************************