On March 9, Mark & Steven Bornfeld DDS inquired, in pertinent part:

(snip)

I am not qualified to give a technical answer. However, Vantas is an LHRH
agonist, just as the other such products. Judging from what I've read, its
primary selling point appears to be the formulation that permits doses to
be administered at yearly intervals.

My anecdotal experience with Zoladex, Lupron and Trelstar is that the
primary difference I've noted is in the hot flush side effect: more with
Trelstar, less with Zoladex and minimal with Lupron.

Information can be found at: www.drugs.com/vantas.html

See above.

That's a question that only a properly-trained medic should answer. Again
anecdotally, once I treated with Casodex (bicalutamide) when starting on
Zoladex, I never had to do so again when changing to another LHRH agonist.

Regards,

Steve J

(My mail program is acting up. Hope this comes out legible.)

I'm not an expert.  Your doctor knows (or should know) a lot
more about this than I do.  But having said that, I'll go on and
venture a non-expert opinion.

It's my understanding that all of the LHRH agonists are equally
effective and achieve the same result.  One reason for this is
that the actual effect (reduction in testosterone production) is
not a direct effect of the drug, but a very indirect effect.  The
drug affects the production of LHRH, which affects the production
of LH, which affects the production of testosterone.  So any
drug that drives LHRH to the threshold level should have the
same effect.  In other words, I expect your doctor is right.

There's an article about these drugs in Wikipedia at:
  http://en.wikipedia.org/wiki/GnRH_agonist

If I read it correctly, the differences between all the drugs
are very minor and primarily affect the rate of degradation
of the drugs in the body.

About the flare, I don't know the answer.  However I would
imagine that, if the drug is given before the effects of the old
drug have worn off, it would be like continuing the old drug,
not starting something new.  The doctor may have more info
about that.

As to side effects, I see that Steve thought he detected
differences between the different drugs in intensity of hot
flashes.  I'm wondering if perhaps that had more to do with other
factors than the drug itself (time of year - is it cold in the house,
how long he had been on the drug since beginning HT, or possibly
others).  In theory, if the side effects are primarily due to the
lack of testosterone rather than direct effects of the drugs, then
the primary side effects will be the same for all of the drugs.

I recommend that you ask the doctor to get a testosterone
reading from your father (there may even be more than one
kind of testosterone reading) _before and after_ the old drug
wears off.  If the testosterone readings are the same under the
new drug as under the old, then you have good evidence that
they both work equally well.  If the testosterone reading goes
up, then you know the new drug isn't doing as good a job.

<OffTopicRant>
Finally, I'm sympathetic to the doctor's problem of getting paid.
"managed care" has often come to mean, "find every conceivable
way of denying payment for anything you can get away with
denying, or anything that the doctor is just too tired of fighting
you for."

My wife (a psychotherapist) is paid by health insurance
companies and she has seen unbelievable amounts of
bald-faced lying, cheating, and stealing by the managed care
companies in attempts to deny her legitimate claims.
</OffTopicRant>

   Alan

I cannot answer the technicalities of your question, but my concern would be
more for the different set or onset of side effects.  If he is asymptomatic
and suffers no side effects, he might realize too late that hassles with
reimbursement are slight comparatively.