Pramipexole may be an effective treatment option in essential tremor.

OBJECTIVE

To perform a pilot study assessing possible efficacy, safety, and optimal dosage of pramipexole in essential tremor.

METHODS

Twenty-nine patients with essential tremor were enrolled into this 16-week-long study. After recording baseline condition, 2 different dosages of immediate-release formulation of pramipexole were evaluated (1.05 mg/d and 2.1 mg/d in 3 identical dosages). Subsequently, immediate- and extended-release formulations were compared. The Fahn-Tolosa-Marin Tremor Rating Scale, Activities of Daily Living, the EuroQol instrument for detecting health-related outcome, and Clinical Global Impression of Improvement Scale were obtained. After completing the study, a rater blinded to the treatment reassessed the tremor rating scales based on video recordings.

RESULTS

Twenty-four patients (82.6%) completed the study. Causes for discontinuation were adverse effects of pramipexole: intolerable nausea (n = 3), daytime sleepiness (n = 1), and anxiety (n = 1). Twenty-one patients had a score of less than 3 on the Clinical Global Impression of Improvement Scale (treatment responders, 72.4%). All the major outcome values demonstrated significant improvement. The severity of tremor was reduced by 52.0% (43.7 vs 20.8 points, Fahn-Tolosa-Marin Tremor Rating Scale), and the EuroQol instrument for detecting health-related outcome score improved from 0.69 to 0.91 (P < 0.01). The dose of 2.1 mg was more effective than that of 1.05 mg; however, both the immediate- and extended-release formulations were equally efficacious. After completion of the study, 15 patients (51.7% of the enrolled patients) wanted to remain on pramipexole treatment.

CONCLUSIONS

This pilot study suggests that pramipexole may be effective in the treatment of essential tremor. However, further controlled studies are required.