Lodaloda,

Regarding carbidopa/levodopa, a dose of 25/100mg three times per day is, I think (I am not a doctor) a bit on the low side (unless your mother is a very small lady) to conclusively show that she will never respond to levodopa.

The pharmacokinetics of levodopa show that the maximum concentration of levodopa occurs about 60 minutes after taking the dose and, thereafter halve about every 90 minutes. These values are affected by what you eat. There is little carry over from day to day. So, any effect should be seen quickly. If you're not seeing an effect that could mean that the dose is not high enough to get her to the "on" threshold or that she doesn't respond to levodopa.

Levodopa is better at reducing stiffness than reducing tremor.

If she really does not respond to levodopa, that would make it worth considering an alternative diagnosis. Your doctor will probably want to give time for the effectiveness of the amantadine to become clear. But, when this is done, and if it is not effective, it may be worth titrating your mother's levodopa dose up to 600mg per day.

It may be worth taking the side-to-side tap test.

Parkinson's Disease Measurement: PwP, surveys, trials, analysis

As training, run the test 10 times, and throw away the results. Then do the test to this schedule: 30 minutes before the morning dose, 15 minutes before, just before the dose, then every 15 minutes for 3 hours. A response to levodopa is shown by higher scores as the dose kicks in.

John