Table 1.

Converting anti-parkinson medications to levodopa equivalent daily dose

Drug	Conversion factor
Immediate-release levodopa	1 ×
Controlled-release levodopa	0. ×75a
Carbidopa/levodopa extended-release capsules (Rytary)	LD 0.5 ×b
Entacapone (or Stalevo)	LD 0.33 ×c
Tolcapone	LD 0.5 ×c
Pramipexole (as salt)	100 ×
Ropinirole	20 ×
Rotigotine	30 ×
Selegiline 10 mg (oral)	10 ×
Selegiline 1.25 mg (sublingual)	80 ×
Rasagiline	100 ×
Amantadine	1 ×
Apomorphine	10 ×

LD levodopa dose

^aBased on the authors’ clinical experience, a conversion factor of × 0.6–0.7 may be used for carbidopa/levodopa controlled release (e.g., Sinemet^® CR, Merck & Co. Inc, Whitehouse Station, NJ)

^bBased on the conversion from carbidopa/levodopa immediate release to Rytary (Impax Laboratories, Inc., Hayward, CA) published by Pahwa and Lyons [25]

^cTo calculate the total levodopa equivalent daily dose for catechol-O-methyl transferase (COMT) inhibitors (i.e., entacapone, tolcapone), the total levodopa amount (including controlled-release levodopa if COMT inhibitor is given simultaneously) should be calculated then multiplied by the appropriate value. For Stalevo^® (Novartis Pharmaceuticals Corp., East Hanover, NJ), the levodopa and COMT inhibitor should be split and calculated separately

Adapted from Tomlinson et al. [24]