beta-adrenergic blocking agent

beta-adrenergic blocking agent
    n 1: any of various drugs used in treating hypertension or
         arrhythmia; decreases force and rate of heart contractions
         by blocking beta-adrenergic receptors of the autonomic
         nervous system [syn: {beta blocker}, {beta-blocking agent},
         {beta-adrenergic blocker}, {beta-adrenergic blocking
         agent}]