Parkinson's Measurement     Home         PDMeasure         Postings         Data         Studies         Tools         Philosophy         Contact        
Research by PwP for PwP   NEW... PDMeasure: integrated survey and test environment.  See.       NEW... Levodopa equivalent minute by minute pharmacokinetics.   See.  

Levodopa Equivalent Dose Calculator

This page is for people with Parkinson's (PwP). It calculates the contribution made by each of your Parkinson's drugs, using, as a common denominator, an estimate of the levodopa equivalent dose (LED). The LED is the amount of levodopa (taken with carbidopa) that has a similar effect as the drug taken. Adding together all the LEDs in a day gives the levodopa equivalent daily dose (LEDD).

To find your LEDD, enter your data in the green boxes. Where a drug contains levodopa and other active components, input the levodopa dose only. Then press the blue "Calculate" button.

Drug Dose(mg) Conversion
Factor
LED(mg) Comments
Total, LEDD (mg) =

Conversion factors

The conversion factors used are shown in the table below. Where the literature shows large variations in what is thought to be the correct conversion factor to use, a tuple is shown meaning (lowest estimate/highest estimate/average estimate)

DrugConv FactorSources and Notes
Amantadine1[1]
Apomorphine 10[1][2] (8/10/8.25)
Azilect 10Brand name of rasagiline.
Bromocriptine 10[2]
Cabergoline 80[2] (66.6/100/80.12)
Duodopa 1.11[1]*
Entacapone[1] 0.33*L-Dopa. Enter Levodopa with Entacapone
Levodopa1[1]*
LevodopaCR0.75[1]*
Levodopa with Entacapone1.33Inferred from [1]*.
Levodopa with Tolcapone1.5Inferred from [1]*.
Lisuride100[2]
Madopar1Brand name of levodopa and benserazide.*
Mirapex100Brand name of pramipexole
Perglide100[2]
Pramipexole100[1][2] (67,100,89)
Rasagiline100[1] Maximum effect found with 1mg.
Requip20Brand name of ropinirole
RequipXL20Inferred from [3]. Brand name of ropinirole CR
Ropinirole20[1][2] (16.67,33.3,21.3)
RopiniroleCR20See RequipXL.
Rotigotine 30[1]
Rytary 30Estimate based on [4]*
SelegilineOral 10[1]
SelegilineSublingual 80[1]
Sinemet 1Brand name of levopdopa with carbidopa.*
SinemetCR 0.75Brand name of controlled release levopdopa with carbidopa.*
Stalevo 1.33[1][2] (1.2,1.33,1.25)*
Tolcapone[1] 0.5*L-Dopa. Enter Levodopa with Tolcapone

Note *: This drug contains multiple components. Input the levodopa dose only.

Limitations of this approach

The conversion factors are clearly rounded which shows that they are estimates.

Different sources give different conversion factors. The range of the estimates for ropinirole, a factor of two, is especially large.

The analysis does not take into account the timing of the doses, differences in effectiveness from person to person, the time it takes a drug to have an effect and the duration of its activity.

References

[1] "Levodopa Dose Equivalency: A Systematic Review"
Dr Claire Smith, Birmingham Clinical Trials Unit
8th June 2010
Smith et al.

[2] "Cálculo de unidades de equivalencia de levodopa en enfermedad de Parkinson"
Amin Cervantes-Arriaga1, Mayela Rodríguez-Violante1, Alejandra Villar-Velarde, Teresa Corona
Arch Neurocien (Mex) Vol. 14, No. 2: 116-119; 2009
Range of estimate data

[3] GSK prescribing information for RequipXL
RequipXL prescribing information

[4] Rytary prescribing information
Revised 1/2015
Rytary prescribing information