【評論主題】60. 張先生因前列腺肥大而有排尿困難的困境，陳醫師給予 phentolamine 治療，請問其作用機理為何？(A)阻斷 α-adrenergic receptors (B)阻斷 β-adrenerg

【評論內容】Phentolamine- nonselective a-adrenergic blocker