Immediate-release and controlled-release carbidopa/levodopa in PD: a 5-year randomized multicenter study....

Area of Science:

• Neurology
• Pharmacology

Background:

• Parkinson's disease (PD) management involves carbidopa/levodopa therapy.
• Hypothesized that sustained-release (CR) carbidopa/levodopa would reduce long-term complications compared to immediate-release (IR).

Purpose of the Study:

• To compare the long-term efficacy and safety of immediate-release (IR) and sustained-release (CR) carbidopa/levodopa in levodopa-naive PD patients.
• To assess the development of motor fluctuations and dyskinesias over a 5-year period.

Main Methods:

• Blinded, randomized parallel study involving 618 levodopa-naive PD patients across 36 international centers.
• Efficacy and adverse reactions monitored every 3 months for 5 years.
• Motor fluctuations, dyskinesias, and quality of life (Nottingham Health Profile) assessed using patient diaries, physician questionnaires, and validated scales (UPDRS).

Main Results:

• Approximately 60% of patients completed the 5-year trial.
• No significant difference in the incidence of motor fluctuations or dyskinesia between IR (20.6%) and CR (21.8%) groups.
• Sustained-release (CR) showed superiority in Activities of Daily Living (UPDRS) and aspects of quality of life (NHP), potentially due to higher doses used.

Conclusions:

• Both IR and CR carbidopa/levodopa maintained similar PD symptom control over 5 years compared to baseline.
• Low incidence of motor fluctuations/dyskinesia observed in both groups, possibly due to relatively low levodopa doses.
• The choice between IR and CR carbidopa/levodopa may depend on specific patient needs and tolerance, with CR offering some quality-of-life benefits.