Adjuvant therapy of parkinsonian tremor

The effect of long-acting propranolol hydrochloride (160 mg/d), primidone (250 mg at night), and clonazepam (4 mg/d) on the resting, postural, and kinetic component of tremor was investigated in ten parkinsonian patients in a double-blind crossover design. Tremor was assessed by patient opinion, clinical scoring, and accelerometer recordings. The amplitude and frequency of tremorgrams were determined by spectral analysis. Most patients preferred long-acting propranolol and chose to continue taking the drug. The mean clinical score for resting and postural tremor was significantly decreased by long-acting propranolol but not by primidone or clonazepam. Long-acting propranolol reduced the mean amplitude of resting tremor by 70% and the mean amplitude of postural tremor by 50%. Mean tremor amplitudes were not changed by primidone or clonazepam. Tremor frequency was unaltered by the drugs. No side effects occurred with long-acting propranolol but adverse reactions were common with primidone and clonazepam. Long-acting propranolol is a useful adjuvant therapy for the tremors associated with Parkinson's disease.