My mother (age 85) had the exact same problem....I finally got her onto 1/2 of a 25/100 CR (controlled release) Sinemet in the AM and 1/2 of the 25/100 at noon by getting her doctor to give us a prescription for lodosyn (which is an added dose of carbidopa to compensate for the nausea) She takes half of a lodosyn tablet in the AM with the 1/2 of the Sinemet and the same at noon. Note she eats right after taking the pills. She also takes a 2.5mg parlodel pill in the early AM, AM, Noon, and Night. I also found by accident that a vitamin B-100 (B complex with multiple B vitamins) supplement made her nauseas even under the above scenerio...and after reading about B6 counteracting the anti-nausea effect of carbidopa...concluded that the B6 in the B-100 complex vitamin was causing the problem... sure enough ...when the B-100 was stopped the nausea again went away....I hope these experiences are helpful to you....PS my mother is now much improved....and has no nausea problems. Regards, Mike