On Wed 29 Jan, Marty Rose wrote:
> I have recently (this week) started a more vigorous excercise routine.
> I have been pretty inactive since summer. My questions concern Sinemet
> requirements whe exercising. I am noticing that it wears off sooner
> than normal. Do we need to increase the dosage when exercising and by
> how much? Thanks for any feed back you might give me.
>
> Marty Rose 56/PD 9 years
> [log in to unmask]
>
>
Hello Marty, your question has reminded me that this point was the subject
of an interesting discussion which I was having with Pat Reilly around the
beginning of December 1996. We were running out of steam a little when
Mark Hirsch, who it appears is a Doctor at Johns Hopkins University.
School of Medicine popped up with some very interesting references of
Published articles in the medical journals, which may have a bearing on
the subject.
I have since then been trying to get hold of these reports, and have
managed to locate 2 of them - The other one does not seem to exist.
However ,there is quite enough in the two reports which I have. I will
be referring to a paper entitled "Bliod levodopa levels and Unified
Parkinson's Disease Rating Scale function: With and Without exercise."
(Neurology 1993; 43: 1040-1042 I will refer to this as paper A
The second paper, Titled "The effect of exercise on levodopa absorption"
sounds ideal, but in my view was a little too ambitious, attempting to
cater for so many variables that the basic results are inconsistent and
I chose not to use them.
Paper A raises one highly significant point which all would-be athletes
with PD would be advised to note; that is the importance of getting the
right timing of your levodopa tablets before you start exercising: It
takes between 30 and 60 minutes for a levodopa tablet to take effect (i.e.
to travel from the digestive system to the brain. If you start exercising
before the tablet has completed its journey, the physical exercise tends
to draw the blood supply away from the stomach, towards the skeletal
muscles to provide them with increased oxygen flow. The result is that a
reduced quantity of levodopa arrives at the brain, and for a shorter
length of time.
Having taken that variable out of the equation by starting all their
tests 1 hour after ingesting the tablet, the authors found that there
were No Changes in the blood plasma levels in the group carrying out
vigorous exercise, and those resting. also there was no change in the
effective duration of the tablets.
SUMMARY
1) If you start exercising less then 1 hour after taking a levodopa tablet,
you will experience a reduced plasma concentration ( The less elapsed
time, the greater the reduction ) AND the duration of the tablet will
be reduced.
2) If you wait 1 hour before exercising, there should be no effect on the
timing or effectiveness of the tablet.
My position last year was that initially I thought that there should be no
effect on the timing, although I did think that due to the generally
increased blood flow in the body, the levodopa should complete its
journey to the brain more quickly, resulting in more levodopa for a shorter
time. ( Not a very big effect though.)
So, Marty, the question is: how soon do you start exercise, after taking
your tablet ?
Regards,
--
Brian Collins <[log in to unmask]>
