The treatment of hypertension with drugs that interfere with activity of the sympathetic neuron renders the sympathetic less able to respond to acute physiological stress, often resulting in excessive postural and exercise hypotension. The hypotensive action of propranolol, a beta-adrenergic receptor blocking drug, has been previously reported (Prichard and Gillam, 1964; Prichard, 1966).
In our series of 109 hypertensive patients treated with propranolol, we reported a group of 80 patients whose blood pressure had been previously controlled with bethanidine, guanethidine, or methyldopa. On these drugs that were previously administered 46 of the 80 patients achieved supine or standing diastolic pressures