Hi Robert,
With 4 doses you are approaching the upper limit of what is advised these days, especially for younger people.

What interested me about your post was that you talked about limited response. I experienced this on a similar dosage. It wasn't until entacapone was added that I started to get a good response, and I now take less, and have less fluctuation.

If your neuros think you are on a high-ish dose you could ask them to help you find a means to extend the effectiveness of meds you are on.

You could also try taking you 6 x 100/25 as four doses of 1 1/2 tablets instead of increasing your overall intake........

Usually I get a really good half an hour just before starting to slide into an off, I try to catch this time to take the next dose - these days it corresponds to about 3.45 hours, though it used to be about an hour more. There are little signs that I am starting to slide, if I pay attention I usually make it at the right time, and the clock will back me up!

just ideas, hope you manage to get it sorted out......

Lindy