Topic overview

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α₁-blockers such as prazosin, terazosin, and doxazosin lower systemic vascular resistance and venous return, with little long-term change in heart rate. Some agents, including tamsulosin and alfuzosin, are more uroselective and are used for BPH symptoms. Other applications include pheochromocytoma-related blood-pressure control, Raynaud phenomenon, and prazosin for PTSD nightmares. A key safety issue is first-dose orthostatic hypotension or syncope; low-dose initiation, bedtime administration, and monitoring supine and standing blood pressure are emphasized. Dizziness and other adverse effects, potential additive hypotension with PDE-5 inhibitors, and caution in volume depletion or severe heart failure also matter. Because outcome evidence found higher heart-failure risk than with thiazides, these drugs are generally positioned as adjuncts for hypertension.