Alpha 1 Adrenoreceptor Antagonists

KEY POINTS AND PRACTICAL RECOMMENDATIONS: • α Antagonists lower blood pressure by selectively blocking post-synaptic α(1) -adrenoreceptors, which antagonizes catecholamine-induced constriction of the arterial and venous vascular beds. • α(1) -Adrenoreceptor antagonists are not indicated for initial, first-line antihypertensive therapy; however, they can be added to most other antihypertensive drug classes in--preferably diuretic-containing--drug regimens. • When used over time, these agents cause expansion of the extracellular fluid and plasma volumes that typically manifests as weight gain and an attenuation of the blood pressure-lowering efficacy in persons who are consuming usual amounts of dietary sodium. • Utilization of α(1) -adrenoreceptor antagonists with diuretics such as chlorthalidone or hydrochlorothiazide is beneficial because these agents minimize the α antagonist-induced expansion of the extracellular and plasma volumes while providing significant incremental reductions in blood pressure. • α(1) -Adrenoreceptor antagonists are especially useful in men with benign prostatic hypertrophy because they increase mean and peak urinary flow rates as well as reduce lower urinary tract symptoms. • α(1) -Adrenoreceptor antagonists are contraindicated in persons with heart failure because of their aforementioned ability to expand extracellular and plasma volumes.