Guanabenz (2,6 dichlorobenzylidene amino guanidine acetate) is a new antihypertensive whose mechanism of action appears to involve both central alpha adrenergic stimulation leading to suppression of sympathetic nervous system activity from bulbar vasoconstriction centers as welt as peripheral adrenergic neuron blockade. In this study, the drug was shown to produce a statisticalty and clinically significant decrease in blood pressure during a 4-wk placebo-controlted double-blind study. For three additional months continued efficacy and safety were shown under open conditions in 17 hypertensive patients. Mild sedation occurred, but there were no postural hypotension, tachycardia, evidence of sodium retention, gastrointestinal disturbances, or electrocardiographic (ECG) abnormalities. Noninvasive parameters of cardiac performance in JO patients after single doses of guanabenz showed no significant changes. Although the numbers of patients were relatively small, the data suggest that this new drug may be a useful antihypertensive agent that warrants further investigation.”Guanabenz (2,6 dichlorobenzylidene amino guanidine acetate) is a new antihypertensive whose mechanism of action appears to involve both central alpha adrenergic stimulation leading to suppression of sympathetic nervous system activity from bulbar vasoconstriction centers as welt as peripheral adrenergic neuron blockade. In this study, the drug was shown to produce a statisticalty and clinically significant decrease in blood pressure during a 4-wk placebo-controlted double-blind study. For three additional months continued efficacy and safety were shown under open conditions in 17 hypertensive patients. Mild sedation occurred, but there were no postural hypotension, tachycardia, evidence of sodium retention, gastrointestinal disturbances, or electrocardiographic (ECG) abnormalities. Noninvasive parameters of cardiac performance in JO patients after single doses of guanabenz showed no significant changes. Although the numbers of patients were relatively small, the data suggest that this new drug may be a useful antihypertensive agent that warrants further investigation.