Brian, where does your source get the information that the center of a CR is
any different than the rest of the tablet? This would imply the tablet is
made in layers (which it is not) and each layer may be different (which does
not exist).  Sinement CR comes in two sizes 50/200 which has a score mark and
25/100 which does not have a score mark.  The 50/200 can be broken and in
published reports actually yields more benefit when two halfs are taken
rather than a whole tablet.  The PDR says that the bioavailability of
levodopa in elderly patients (ages 55 to 66) is 70-75%.  The bioavailability
in young patients is 44%.  When questioned about the difference, one
neurologist says that the bioavailability is so variable that if the drug
works, use it, if it doesn't try another approach.  Another neurologist says
that young people have a more active digestive system causing the tablet to
pass through too fast.  I know the first explanation is correct, CR is highly
variable.  The second explanation makes sense to me also.

When CR was first released it was given to almost all patients as the
solution to all problems.  I remember visiting my neurologist during those
days and he had three stacks of patient folders on his desk waiting for a
return call.

If you read the literature from the manufacture, 50/200 CR taken every six
hours is expected to yield a smoother blood plasma level then two regular
25/100 taken at 3 hour intervals. What is not shown is the potential OFF
period that may be experienced while the first CR dies and the second CR
becomes productive.  If you think of it, the last hour of the first CR is
nosediving in benefit yet it will take as much as two hours to reach peak
blood plasma level with the second CR.  This leaves a low that may be an OFF
between tablets.  One way to solve this is to start the second CR 5 hours
after the first.

A little cost analysis.  Sinemet CR 50/200 is usually priced at twice that of
a regular Sinemet 25/100.  Lets assume regular Sinemet 25/100 costs 50 cents
than a Sinemet CR 50/200 costs $1.00.  If we need to take a CR every 5 hours
the cost of a CR becomes $1.20.  Furthermore, if you receive only 70%
bioavailability, this puts the cost at over $1.71.  Since this is more likely
the case, the cost is actually 3.5 times the cost of regular Sinement.  If
you are a young person getting only 44% bioavailability the cost comparison
makes the CR priced at $2.73.  This is 5.5 times the cost of regular Sinemet.
 If you are paying for your meds out of your own pocket, I hope I have given
you something to think about.

There is the arguement that maybe the patient was getting too much levodopa
from the two 25/100 regular tablets.  If the analysis is done based on a
levodopa yield of .7 from the regular Sinemet (cut in half, cut a half in
half to get .75) the numbers come out the same.

Happy CRing or is it CRying!

I should state the advantages of CR:
  1.  A more level release of levodopa is better then the bang, bang that is
experienced with two regular.  Over the long run doctors have guessed that
the bang, bang may be harmful.

  2.  The patient only takes drugs every 5 or 6 hours as compared to every
three hours. Patients, of which I am one, do not like to take tablets
frequently.

  3.  Your doctor may say it is important you stay on the leading edge of
drug therapy.  Who is telling this to the doctor?  Patients or Pharm Sales?

Regards,
Alan Bonander