ISSUE 2 OF THIS MESSAGE=20
My apologies to everyone for accidentally including Tolcapone in my list of
Dopamine Agonists. It is of course a COMT inhibitor and has nothing to do
with this subject. (Thanks for pointing it out Ron)
I would be interested if anyone has additional material or
experience relevant to this post.
I recently had the opportunity of a long chat with my neurologist, who=20
is a specialist in Parkinson's Disease, and is certainly the most informed=20
of the many specialists who I have dealt with over the course of 19 years=20
with PD. We were discussing the relative merits of the various Dopamine=20
Agonists. I commented that I did not see any difference in the performance=20
of these drugs as far as performing their basic function of providing a=20
Dopamine substitute without provoking dyskinesias. I was somewhat surprised
to find that he fully agreed with me! It appears that there is virtually no
research being done or previously done comparing the performance of the=20
various agonists, and it appears that the drug manufacturers show no=20
enthusiasm for doing such tests. (There's a challenge for our researchers)
=20
Since writing issue 1 of this note, I have discovered a reference to one=20
fairly serious comparative study, which compared the effectivness of=20
Bromocriptine and Permax when used in conjunction with levodopa.=20
(LeWitt PA, Ward CD, Larsen TA, et al:- Comparison of Pergolide and=20
Bromocriptine therapy in Parkinsonism. Neurology 1983:33; 1009-14).
The conclusion of the test was "The 2 drugs were judged to be clinically=20
similar with respect to both antiparkinsonian efficacy and adverse effects.
Although this was a double-blind study, the reviewer does make a number of=20
criticisms of the detail of the the experiment but, for what it's worth,
it does support my basic point which is:
=20
1) All the Dopamine agonists perform their basic function, and there is no
difference in the performance of one versus the other. If you are trying to
increase your On/Off margins, or reduce your Sinemet/Madopar dosage by
increasing the agonist dosage, ALL the agonists will do the job, and one is=20
as good as another.
=20
Ron responded to my first issue of this note with a lengthy account which I
suspect came straight out of the drug makers press release. It makes my=20
point nicely which is that until proven by clinical tests, the sort of
high-sounding claims quoted by Ron are best regarded as waffle or flute music
(as we call it). =20
=20
2) Where the dopamine agonists DO differ is in the tendency to produce=20
unwanted side effects. Generalisation is impossible here: it is definitely a=20
case of 'One man's meat is=A0another man's poison'. All that can be done is, if=20
your particular Agonist is giving you trouble, try one of the others. This
is the ONLY valid reason for changing agonists. With the number of options=20
now available, there are good grounds for expecting that one or more of them=20
will prove to be satisfactory for you. I have listed below the currently
available agonists; let me know if I missed any. (Not all of these will be=20
available in a specific country)
=20
Apomorphine
Bromocriptine (Parlodel)
Lisuride (Revanil)
Pergolide (Permax, Celanse)
Cabergoline (Cabaser)
Ropinirole (Requip)
Pramipexole (Mirapex)
=20
=20
--=20
Brian Collins <[log in to unmask]>
