Alpha blockers ✓ Passing Score: 50% 📝 Questions: 15 🎓 Practice Quiz Welcome! This is a practice quiz to test your knowledge. Please enter your details below to participate. Your results will be emailed to you upon completion. Your Information Name * Email * Start Quiz → Question 1 of 15 1 Non-selective alpha-blockers, such as phenoxybenzamine, block which combination of adrenergic receptors? * Both $\\alpha_1$ and $\\alpha_2$ receptors All $\\alpha$ and $\\beta$ receptors Only $\\alpha_1$ receptors $\\alpha_1$ receptors and $\\beta_1$ receptors Only $\\alpha_2$ receptors 2 Which clinical condition is an FDA-approved indication for the use of selective $\\alpha_1$ blockers like tamsulosin? * Benign Prostatic Hyperplasia (BPH) Migraine prophylaxis Pheochromocytoma crisis management Essential Tremor Congestive Heart Failure 3 Which effect is typically *not* seen as a primary therapeutic outcome when using a selective $\\alpha_1$ blocker for hypertension? * Decreased peripheral vascular resistance Increased systemic vascular resistance Reduced blood pressure Increased venous capacitance Reduced afterload 4 Which receptor subtype is primarily responsible for the vasoconstrictive effects mediated by norepinephrine in the peripheral vasculature? * $\\beta_2$ Muscarinic M2 $\\alpha_1$ $\\beta_1$ $\\alpha_2$ 5 Which of the following drugs is an irreversible, non-competitive antagonist often used specifically to treat hypertension associated with pheochromocytoma? * Tamsulosin Terazosin Prazosin Phenoxybenzamine Alfuzosin 6 Drugs like yohimbine block the auto-inhibitory feedback mechanism mediated by which receptors, leading to increased central norepinephrine release? * $\\beta_2$ $\\beta_1$ $\\alpha_2$ $\\alpha_1$ Dopamine D1 7 Which selective $\\alpha_1$ blocker is often preferred for treating BPH because it exhibits greater selectivity for the $\\alpha_{1A}$ subtype found predominantly in the prostate? * Alfuzosin Doxazosin Prazosin Tamsulosin Terazosin 8 A major cardiovascular side effect associated with the blockade of $\\alpha_2$ receptors (especially non-selective blockade) is reflex tachycardia. This occurs because: * Peripheral vasodilation reduces afterload, causing a compensatory increase in heart rate via the baroreflex. $\\alpha_2$ blockade directly activates cardiac $\\beta_1$ receptors. Peripheral vasodilation reduces venous return, stimulating baroreflexes. $\\alpha_2$ blockade prevents central sympathetic outflow. $\\alpha_2$ blockade directly increases heart rate via CNS action. 9 A common, potentially serious side effect associated with the *first dose* of an $\\alpha_1$ blocker used for hypertension or BPH is orthostatic hypotension, often termed the \"first-dose phenomenon.\" Which drug is most notorious for this effect due to its high receptor affinity? * Tamsulosin Prazosin Doxazosin Terazosin Phenoxybenzamine 10 What is the primary physiological result of blocking presynaptic $\\alpha_2$ receptors on sympathetic nerve terminals? * Reduced breakdown of circulating epinephrine. Increased release of norepinephrine. Direct blockade of postsynaptic $\\alpha_1$ receptors. Decreased release of norepinephrine. Increased reuptake of norepinephrine. 11 The primary mechanism by which prazosin treats hypertension is through the blockade of which receptors? * Pre-synaptic $\\alpha_1$ receptors Post-synaptic $\\alpha_2$ receptors Angiotensin II Type 1 receptors $\\beta_1$ receptors in the heart Post-synaptic $\\alpha_1$ receptors 12 Which receptor subtype blockade is primarily responsible for the ejaculatory dysfunction sometimes reported with alpha-blocker use in BPH patients? * $\\alpha_{1A}$ blockade in the vas deferens/ejaculatory ducts $\\beta_2$ blockade $\\alpha_{1D}$ blockade in the urethra $\\alpha_1$ blockade in the bladder neck $\\alpha_2$ blockade centrally 13 In the context of treating pheochromocytoma, alpha-blockade must precede beta-blockade. Why is this sequence critical? * Beta-blockade first causes profound hypotension. Alpha-blockade is required to sensitize the heart to beta-blockers. Alpha-blockers require prior cardiac depression to work. Beta-blockers are ineffective against catecholamines. Beta-blockade first causes unopposed $\\alpha$-mediated vasoconstriction and potentially hypertensive crisis. 14 How do $\\alpha_2$ agonists (like clonidine) differ fundamentally from $\\alpha_2$ antagonists (like yohimbine) in terms of central sympathetic outflow? * Agonists decrease outflow; antagonists increase outflow. Agonists increase outflow; antagonists decrease outflow. Both decrease central sympathetic outflow. $\\alpha_2$ receptors only modulate peripheral tone. Both increase central sympathetic outflow. 15 Which drug is classified as a selective $\\alpha_1$ blocker with an extended duration of action, allowing for once-daily dosing for both hypertension and BPH? * Terazosin Prazosin Yohimbine Esmolol Phenoxybenzamine ← Previous Next → Submit Quiz ✓
