Background
My mom started on madopar about 3 years ago, didn't work well, so started sinemet about 2 years ago, which stopped the bradykinesia and generally helped. She also takes a small dose of lexapro (SSRI) for depression and a generic multivitamin.

Sinemet dosage
The neuro started her on 2 x 25/100 sinemet three times a day. She developed tardive dyskinesia (pursed lips and movement in mouth area) some time after this, so neuro told her to only take 2 x sinemet (25/100) once in the morning and again once in the afternoon. My mom did that for a while, but then decided on her own to cut back to taking just 2 sinemet 25/100 in the morning, which is what she has been doing for the last year.

Typical Day
Her day goes like this (I'm going to use my own relative scale from 1-10 for PD symptoms, with 10 being the best she feels when she's "on"):

9:00am - [7.5 out of 10] - Wakes up, feels relatively OK and takes her 2 x sinemet (25/100); typically makes her feel sightly nauseated.

9:30 - 10:00am [10 out of 10] - Sinemet kicks in; eats breakfast. Good energy level, can go for a brisk 45 minute walk without problems.

2:00pm [4 out of 10] - Seems like this is when she starts going "off", left hand clenches up, muscle rigidity in her neck, feeling generally tight.

3:00pm+ [7.5 out of 10] - After resting in a chair or bed for about an hour, she feels better again, more or less like she does when she wakes up. She has not taken any more sinemet or other supplements. She gets through the rest of the day feeling generally well, but at a lower energy level than when she is "on" with her Sinemet.

New information after skipping 2 days of Sinemet dosages:

Day 1 without any Sinemet ... she felt about a 7.5 out of 10
Day 2 without any Sinemet ... bradykinesia kicked in, very low energy, obviously missing the Sinemet ... 4 out of 10

If she wasn't taking sinemet at all, I'm fairly sure her bradykinesia would re-emerge along with her blank stare and the other PD symptoms she originally showed a few years ago.

Questions/personal thoughts related to these observations (please keep in mind that I have no real experience with PD, just what I've read):

1. What hypothesis can you draw based on the fact that she can function fairly well (7.5 out of 10) in the afternoons with only a single dose of sinemet in the morning, and that she feels her worse (4 out of 10) when that dose is wearing off at around 2pm every day ... and also on the 2nd day after not taking any sinemet?

Here are some of my thoughts, which of course are just wild guesses based on the little I know:

a. there is still enough residual l-dopa from the morning sinemet or cumulatively in her system to allow her to function at a 7.5 until the next day or even 2 days (since Day 1 of not taking sinemet, she still felt about at 7.5 out of 10). The half-life of sinemet is about 2 hours, but don't know about the cumulative, long-term effect?

b. her brain is able to and expects to produce some l-dopa in the afternoons ... enough to feel about a 7.5, but has learned to expect an external source of l-dopa in the morning ... the combination of the 2 get her by?

2. The fact that she doesn't take any sinemet in the afternoon and is able to function at a slightly lower level of energy (7.5), but doesn't "need" the Sinemet, makes me want to talk to her neuro (or not?) about looking into an alternative, more natural, and complementary therapy for the afternoon. The idea being, that if it works, maybe it can become her primary treatment and reduce/eliminate the Sinemet over time. It seems like it's a good "test bed" (a.m. vs. p.m treatment) since in both cases she feels around a 7.5 before taking anything.

I am especially thinking about some combination or subset of the precursors to l-dopa ... l-tyrosine, folic acid (precursor to Tetrahydrofolic acid), Nicotinamide (precursor to NADH) or NADH, and iron [I haven't checked drug/supplement contraindications yet]. Theoretically, I think it would make sense to try boosting her internal l-dopa biosynthesis from l-tyrosine by supplementing with l-dopa precursors that may be lacking ... instead of only focusing on external delivery of l-dopa. I've read a number of studies where some people have had success with l-tyrosine and even iron to reduce PD symptoms or at least reduce the level of external l-dopa that they needed to take. Worth a try? Thoughts?

Any insight, thoughts, ideas would be greatly appreciated.