Some additional equivalences, adapted from Wullner et al. [1]:

Total levodopa equivalent dose =
regular levodopa dose × 1 +
levodopa continuous release dose × 0.75 +
pramipexole dose × 67 +
ropinirole dose × 16.67 +
pergolide dose × 100 +
bromocriptine dose × 10 +
cabergoline dose × 50 +
amantadine dose × 0.5 +
selegiline dose × 10 +
rasagiline dose × 100.

Where tolcapone or entapone are added, e.g. Stalevo,
Levodopa equivalent dose =
regular levodopa dose x 1.25

I repeat a point that I made in a previous post: these are only estimates, they vary from author to author and from patient to patient. They do not take into account differing side effects.

In judging the impact you also have to estimate the duration of the effect. For instance, a dose of 100 mg of sinemet may have an effect for, perhaps, 3 hours (it will vary from person to person). Whereas a dose of 1 mg of rasagilene will last for 24 hours. In total effect both are roughly equivalent, but the Sinemet has about 8 times (24/3) the intensity.

The LED approach essentially assumes that the impact of taking more drugs (both of the same and different types) is additive.

This is not the case with rasagilene. For most people the law of diminishing returns applies [2].

"Mean baseline PFS score was 2.2 ± 0.9 units. At 36 weeks, patients receiving placebo showed greater progression of symptoms (0.17 units) from baseline in PFS scores compared with the 1 mg/day (0.03 units) and 2 mg/day rasagiline groups (−0.02 units); the difference versus placebo was significant for both rasagiline groups (P < 0.01)."

It is also possible that the opposite is the case for some combinations of drugs. Brodsky et al. report [3]:

"Pramipexole augmented the motor response to levodopa beyond a simple additive effect and increased the severity of levodopa-induced dyskinesia. When considering a combination of these therapies, an appropriate balance should be maintained regarding gain of motor function vs worsening of dyskinesia."

References

[1] "Transdermal rotigotine for the perioperative management of Parkinson’s disease
Ullrich Wüllner,corresponding author1 Jan Kassubek,2 Per Odin,3 Michael Schwarz,4 Markus Naumann,5 Hermann-Josef Häck,6 Babak Boroojerdi,6 and Heinz Reichmann
j Neural Transm, 2010 July
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2895903/

[2] "Benefits of treatment with rasagiline for fatigue symptoms in patients with early Parkinson's disease"
F. Stocchi*, The ADAGIO investigators
European Journal of Neurology © 2013 EFNS
http://onlinelibrary.wiley.com/doi/1...12205/abstract

[3] "Effects of a Dopamine Agonist on the Pharmacodynamics of Levodopa in Parkinson Disease"
Matthew A. Brodsky, MD; Byung S. Park, PhD; John G. Nutt, MD
Arch Neurol. 2010;67(1):27-32. doi:10.1001/archneurol.2009.287.
http://archneur.jamanetwork.com/arti...ticleid=798841

John