Controlled-release carbidopa-levodopa (Sinemet) in combination with standard Sinemet in advanced Parkinson's disease.

Twelve of 23 patients with Parkinson's disease and motor fluctuations who entered a double-blind study comparing controlled-release carbidopa/levodopa (Sinemet CR-4) with standard Sinemet (SS) continued into open label follow-up on a combination of CR-4 and SS (C/S); the rest continued on CR-4 alone. Significant improvement on C/S compared with CR-4 was noted for shorter duration and reduced disability of dyskinesias, and more hours "on" without dyskinesias (all p less than 0.05). Total number of hours "off" was improved on C/S over SS (p less than 0.01). Sinemet CR-4 proved to be better than C/S for sleep disturbance (p less than 0.05). Although the total number of tablets and doses per day of CR-4 was reduced during the C/S period, total levodopa dosage per day was not significantly changed from either of the previous periods. The C/S therapy for advanced parkinsonism can be more efficacious for fluctuators than either CR-4 or SS alone.