Long‐term tolerability of tetrabenazine in the treatment of hyperkinetic movement disorders

We sought to review the long‐term tolerability of tetrabenazine (TBZ) and seek determinants of tolerability in the treatment of hyperkinetic movement disorders. A retrospective chart review was performed on patients treated with TBZ between 1997 and 2004. Efficacy of TBZ was assessed by a 1‐ to 5‐point response scale (1 = marked reduction in abnormal movements, 5 = worsening). All adverse events (AEs) were captured according to their relationship with study drug. A total of 448 patients (42% male) were treated for a variety of hyperkinesias, including tardive dyskinesia (n = 149), dystonia (n = 132), chorea (n = 98), tics (n = 92), and myoclonus (n = 19). The mean age at onset of the movement disorder was 43.0 ± 24.2 years, with TBZ starting at a mean age of 50.0 ± 22.3 years. Patients remained on treatment for a mean of 2.3 ± 3.4 years. An efficacy response rating of 1 or 2 was sustained in the majority of patients between the first and last visit. Common AEs included drowsiness (25.0%), Parkinsonism (15.4%), depression (7.6%), and akathisia (7.6%). Comparison of log‐likelihood ratios revealed that age was a reliable predictor of Parkinsonism ( P < 0.0001). TBZ is a safe and effective drug for the long‐term treatment of hyperkinetic movement disorders. © 2006 Movement Disorder Society