Please note: grapefruit juice (GJ) can increase the potency of some drugs, and this can have a dangerous effect on some people. Please see your doctor.

I have run an n of 1 trial on me to test the effect of an adding a dose of GJ to an existing daily drug regimen of 5 x 75mg Stalevo (levodopa/carbidopa/entacapone), 1mg rasagiline and 8mg ropinirole CR).

grapefruitJuiceDump.png

Let me explain the testing procedure adopted. I ran four tests, two were controls (75mg Stalevo, no GJ), 2 tested the impact of GJ (one was 75mg Stalevo and 100ml GJ; the other was 75mg Stalevo and 200ml GJ).

Each test involved going for at least 1020 minutes without the ropinirole and rasagiline, 510 minutes without Stalevo, and 360 minutes without food. This is too short a period of time to completely wash out these drugs, but it is thought to be long enough for their remaining residual impact to be limited.

Each test involved doing a lap top version of the side to side tap test every 10 minutes from 20 minutes before a dose until at least 190 minutes after a dose. Each test gives two scores, the number of taps in 30 seconds for each of the left and right hands. Higher scores are good.

https://www.parkinsonsmeasurement.or...eToSideTap.htm

In the over detailed graph above you can see plenty of noise (certainly no statistical significance is claimed). But the classic level, rise, plateau, fall, level pharmacodynamic signature as you go through a dose cycle comes through clearly. There is just a hint that the therapeutic duration is longer for the higher GJ dose.

More testing is required.

John