This is Part 2 of 5 of Living with Levodopa:
3.2 You may come accross the term 'Bio-Availability', and a statement
that the Controlled Release form of the tablets only delivers a certain
percentage of its levodopa to the brain; the reason being that the
controlled release takes place in the lower intestine, where the chemical
attack will erode the levodopa to some extent. This argument sounds
reasonable - All I can say is that I saw little sign of loss in my analysis
of the CR tablets. Perhaps it depends on the Carbidopa concentration
available at the time. You can help by keeping your protein intake down to
a sensible level, and always time your meal to start 20 to 30 minutes AFTER
you have taken your latest tablet. This advice may be in complete
contradiction with some Doctors instructions instructions: I know that
they often advise taking the tablets just after a meal, especially if the
patient is suffering nausea caused by the tablets. This is, in my view, a
total waste of time! The tactic works, in the sense that the nausea is
reduced but only because most of the tablet fails to get through to the
bloodstream. So the nausea may be reduced, but so will the
control of your PD condition. This is a very hit-or-miss way of doing it:
Far better to take less tablet and take it at the '20 mins before the meal'
time, then tackle any nausea problems as detailed in the next section.
3.3 Nausea caused by Sinemet/Madopar}
Nausea is experienced by a small percentage of PWPs. To be deprived of the
use of levodopa would be a really serious event, especially in later years.
However,almost all of these people can be helped: The main causes of nausea
and ways to alleviate the condition are:
3.4 Sensitivity to levodopa An unusually sensitive reaction to levodopa
can often be overcome by starting with very low doses, and gradually working
up to the full dose. In the rare case where even that strategy fails, there
is a levodopa-compatible drug known as Domperidone (or Motillium) which
suppresses the vomit reflex. PWPs taking this drug usually find that when
the Motillium is withdrawn, the nausea reaction has gone.
3.5 Sensitivity to Carbidopa
To achieve its protective role as described in Appendix 1, requires a
minimum of 75 mg of Carbidopa per day: A reasonably safe upper limit is
about 300 mg per day. It is usually possible, once the patient's levodopa
requirements are known ( and the levodopa requirement must take precedence)
to find a
combination of tablets which suit the patient's requirements. symptoms of
excess Carbidopa include nausea, and lack of energy. Excess Carbidopa can
be tackled by referring to Table 1 - It should be possible to find a
combination of tablets with the right levodopa, and with Carbidopa within
the 75 and 300 mg/day range.
3.6 A possibility The evidence for this item is just based on a few
personal observations, and I make no great claims. However for what its
worth: I know some PWPs who need very high levels of levodopa, When I
inquired I learnt that most of them were taking Madopar. One person, who
was taking up to 700 mg of Carbidopa, (and suffering the appropriate
symptoms) cured all his adverse symptoms by switching to Madopar. If you
are in such a situation, and Madopar is available to you, it may be worth
trying.
4.0 Some Special points about the various tablets
4.1 Sinemet 275 (Madopar 250) If I had control of these things, I
would SCRAP all the tablets with more than 100 mg of levodopa, because the
only times that a PWP can tolerate such a large dose are the times when he
should be taking small doses. This fascinating subject is outside the scope
of this booklet
4.2 Sinemet 110, Sinemet Plus, Madopar 125 These tablets are
probably the most-used of all the range, yet they are still no more than a
blunt instrument when it comes to fine-tuning a PWP's dosage.
--
Brian Collins <[log in to unmask]>
