A study of excessive daytime sleepiness and its clinical significance in three groups of Parkinson's disease patients taking pramipexole, cabergoline and levodopa mono and combination therapy.

OBJECTIVE

To determine if therapy with an ergot and a non-ergot dopamine agonist and levodopa confers an increased risk of excessive daytime sleepiness and secondary "sleep attacks" in Parkinson's disease (PD).

METHODS

Comparative study of three clinical groups taking, pramipexole (Group 1, n = 19, 8 monotherapy), cabergoline (Group 2, n = 22, 10 monotherapy), and levodopa monotherapy (Group 3, n = 14). Clinical and demographic characteristics, occurrence of "sleep attacks", and assessment of daytime sleepiness [using the Epworth Sleepiness Scale (ESS)], recorded.

RESULTS

No patients reported "sleep attacks". Mean ESS scores: Group 1 (pramipexole) 8.0 +/- 4.5 (range 0-16), Group 2 (cabergoline) 8.1 +/- 3.9 (range 0-19), Group 3 (levodopa), 8.1 +/- 5.5 (range 1-18). There was no significant difference between groups (p = 0.897). Scores of > or = 16 indicating excessive daytime sleepiness (EDS) were evenly distributed throughout treatment groups, particularly in older patients with more advanced disease.

CONCLUSIONS

a) EDS is not unique to pramipexole therapy and occurs with both cabergoline and levodopa. b) Increasing age, advanced disease, and higher treatment dose appear important predictors for EDS. c) Driving regulations should be reviewed accordingly.