Do forum members know of any tables that show the equivalent doseages of common PD drugs?

For instance, it would be useful to be able to know the approximate effect of:
1 mg levodopa = x mg Sinemet
x mg Sinemet = y mg Stalevo, where x and y are the levodopa content
x mg ropinirole = y mg pramipexole

This information would be useful for anyone changing drugs.

It would also be useful in clinical trials and white ratting as a measurement tool by providing a common denominator, e.g. it would allow statements to be made like "this therapy has the same effect as x mg Sinemet".

Annoyingly, there is a paper on the subject [1], but this is behind a pay-wall.

The best reference I can find is a slide show, "Levodopa Dose Equivalency: A Systematic Review" [2], by Claire Smith, from the Clinical Trials Unit at Birmingham University, UK. This uses the concept of
"LED [levodopa equivalent dose] of a drug as that which produces same anti-parkinsonian effect as 100 mg of immediate release levodopa"

Levodopa (it's not clear whether this includes carbidopa, 1 mg) LED = 1
Stalevo (it's not clear how this value is calculated, 1 mg levodopa) LED = 1.33
Ropinirole (1 mg) LED = 20
Rasagiline (1 mg) LED = 100
(The slide show lists many other drug equivalences.)

From these figures a daily total levodopa can be calculated. For instance, in my case: rasagilene, 1 mg (LED 100); ropinirole, 16 mg (320); Stalevo 4x75 mg levodopa (400). Giving a total daily levodopa equivalent dose of 820 mg.

Please note that the numbers in the slide show are based on a literature review. The papers used are not all in agreement as to the conversion factors. Therefore, the values given above should be taken as estimates.

Also, note that different drugs work by different mechanisms and have different side effects and do not always scale linearly. So they should not be thought of as directly substitutable. For instance, [3] reports that there is little marginal benefit increasing the rasagiline dose above 1 mg.

[1] http://www.ncbi.nlm.nih.gov/pubmed/21069833
[2] http://www.pdmed.bham.ac.uk/investig...LED_Review.ppt
[3] http://dailymed.nlm.nih.gov/dailymed...rchiveid=10668

John