Rasagiline treatment effects on parkinsonian tremor

Tremor is a common symptom of Parkinson's disease (PD). The underlying pathophysiology of parkinsonian rest tremor is not well understood. Rest tremor is less responsive to dopaminergic therapy than are symptoms of bradykinesia and rigidity. This paper reviews the effects of 1 mg daily oral rasagiline, as monotherapy and as adjunct therapy, on parkinsonian tremor. A literature search of the EMBASE database was conducted to identify relevant articles in English published between 2000 and October, 2012 using the search terms "rasagiline," or "Azilect®," or "Agilect®," and refined using the terms "Parkinson's disease" and "clinical trial." Of 22 identified publications, two large placebo-controlled trials of rasagiline monotherapy (TEMPO and ADAGIO) and two large placebo-controlled trials of rasagiline as adjunctive therapy with levodopa (PRESTO and LARGO) specifically evaluated the effect of rasagiline on tremor using the Unified Parkinson's Disease Rating Scale (UPDRS) motor examination. Prospective and post-hoc analyses from these phase III studies show rasagiline monotherapy significantly improved tremor symptoms in early PD, independent of disease duration, compared with placebo. In levodopa-treated patients with motor fluctuations who were already receiving optimized dopaminergic treatment, the addition of rasagiline adjunct therapy significantly improved tremor symptoms. Significant improvement was evident as early as 10 weeks from treatment initiation. Tremor symptoms also improved in a subset of patients with severe tremor when rasagiline was added to their existing PD treatment regimen. These data suggest that rasagiline used as monotherapy and as adjunctive therapy is effective for reducing tremor severity in patients with PD.