Levodopa Equivalent Plasma Levels Calculator


#1

A few weeks ago I posted on Levodopa Equivalent Dose: a way of estimating the effectiveness of an anti-Parkinson's drug in terms of levodopa taken with carbidopa. (Whenever I mention levodopa on its own, please assume that I mean it taken with carbidopa). For instance, 1mg rasagiline has about the same total effectiveness as 100mg levodopa. As far as it went this was OK, but it didn't take into account the intensity of the experience. For instance, the levodopa might only be effective for 4hr, whereas the rasagiline is effective for the whole 24hr. To make the equations balance, the levodopa must be 6 times as intense in its effectiveness as rasagiline. To take this effect into account, I've written a new app. You can run this directly from:

http://www.parkinsonsmeasurement.org/toolBox/pharmacokinetics.htm

You input the times of your doses and what they are. The program draws a graph showing your pseudo-levodopa plasma levels. This allows you to estimate the times at which you may go "off" or have dyskinesias. It also makes it easy to come up with drug regimens which make the total drug output smoother.

I've only implemented this program for a small number of drugs. I'll add to it over the next few days.

In the meantime, I'd be grateful for your comments.

John


#2

Hi

i put in my 'data' times,mg ect, ive no idea what the results mean(my parky head lol) only the graph the rise and fall of the black lines seemed to match or mirror the rise n fall of the coloured lines does that equal what im actually feeling?, i don't feel too far out in myself .


#3

My apologies for not being clearer. The coloured lines show the effect of each dose over time: increasing as it gets in the blood stream, decreasing as it gets destroyed. The black line shows the total of the coloured lines under it. It is an estimate of the power of the anti-Parkinson's medication at each minute during the day.

The app assumes that you can add together the effect of different anti-Parkinson's drugs: levodopa based, agonist, MAO-B inhibitor.

John