Potent and selective dopamine β-hydroxylase (DBH) inhibitor (IC50 = 9 nM). Selective for DBH over 12 other enzymes. Decreases noradrenaline and increases dopamine levels in tissues and plasma in hypertensive rats. Prevents progressive left ventricular dysfunction in an in vivo heart failure model. Also potentiates the stimulus effects of cocaine without producing cocaine-like effects in rats. Orally bioavailable. Purity 98%. MW (observed): 331.81