| Methods |
Randomised double‐blind parallel group study. Randomised by computer generated random number tables with the participants being double‐blinded and the code not being broken until after the database was closed.
Multi‐centred ‐ 15 centres in 7 countries.
Intention‐to‐treat data analysis.
Duration: 6 week parallel group design followed by 3 weeks where the tolcapone groups were crossed over for exploratory purposes. |
| Participants |
97 patients, 12 patients withdrew, 6 for adverse events (three in each of the tolcapone groups), the remainder withdrew for other reasons (2 from placebo, 1 in the 200 mg group, 3 in the 400 mg group).
62 men. Mean age 66 years, mean H&Y 'on' 2.2, 'off' 2.5, Mean levodopa dose 662 mg/day.
Inclusion criteria: Patients with moderately advanced PD whose wearing‐off of levodopa effects had been successfully controlled by relatively frequent dosage. |
| Interventions |
Patients received 200 mg tid tolcapone (n=32), 400 mg tid tolcapone (n=32) or placebo (n=33). Riboflavin (0.5 mg) was included in the placebo tablets to mimic the yellow discolouration in urine that occurs with tolcapone as a harmless side‐effect.
Selegiline and apomorphine were not permitted. Concomitant use of other types of antiparkinsonian medications was allowed if the dosage regime had been stable for 2 months before study entry and remained unchanged throughout the study. Nonselective MAOI's were prohibited during the study. High protein‐binding drugs were avoided. |
| Outcomes |
Levodopa dose
Number of doses
IGA motor signs severity
UPDRS motor
UPDRS ADL (on)
UPDRS mood
Adverse events |
| Notes |
TOLCAPONE
Cross‐over 200‐400 mg ‐ weeks 6‐9. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Allocation concealment? |
Low risk |
A ‐ Adequate |
