Requip, a dopamine agonist, is a different drug from Madopar and Sinemet. These last two are very similar, both contain the most effective drug treatment of PD, levodopa, and also a second ingredient (for Madopar this is Benzeraside, for Sinemet, this is Carbidopa) which helps with the most effective way of getting most of the levodopa to your brain.Neurologists seem to have a preference for one over the other,
You do not mention your age? If you are a young Parky you have many years ahead of you and with increased intake of the drugs side effects are more likely and appear sooner, hence consultant's reluctance to increase dose as taking Madopar at three hour intervals tots up nicely. . There is no maximum dose of levodopa (Madopar ), some can tolerate more than others. I take Sinemet every 2-2,5 hours.
3 hiours sleep is not good. Maybe you should ask for some medication at bedtime and/or during the night. I take Sinemet CR (slow release) during night. I was diagnosed 17 years ago.
More rest, ie. better nights could give you better days.