Beta-adrenoreceptor mechanisms in essential tremor: a comparative single dose study of the effect of a non-selective and a beta-2 selective adrenoreceptor antagonist.

In order to study the mode of action of beta-adrenoreceptor antagonists in essential tremor the efficacy of single oral doses of 2, 4 and 10 mg LI 32-468, a peripherally acting, selective beta-2 adrenoreceptor antagonist, was compared with a single oral dose of 120 mg propranolol in a randomised, double blind, placebo controlled trial. Both the lowest dose of LI and propranolol were shown to be equally superior to placebo in attenuating tremor magnitude. This finding supports the contention that the beneficial effect of beta-adrenoreceptor antagonists in essential tremor is mediated via peripheral beta-2 receptor mechanisms.