Alpha-blockers

Sotalol (Betapace) Timolol (Blocadren) Alpha blockers Doxazosin (Cardura) Phenoxybenzamine (Dibenzyline) Prazosin (Minipress) Terazosin (Hytrin) Trimethaphan (Arfonad) 

Beta-adrenergic blockers that are approved for use in hypertension are listed in Table 2 1-4. These drugs are all effective in decreasing blood pressure, but certain beta blockers have additional properties that make 

Nonselective beta blockers (i.e., those with a fairly equal affinity for beta-1 and beta-2 receptors) may produce bronchoconstriction in patients with asthma and similar respiratory disorders. Cardiovascular side effects include excessive depression of heart rate and myocardial contractility as well as orthostatic hypotension. Some of the traditional beta blockers may impair glucose and lipid metabolism, but this effect can be reduced by using one of the newer vasodilating beta blockers such as carvedilol.97 Other side effects include depression, fatigue, gastrointestinal disturbances, and allergic reactions. Beta blockers are generally well tolerated by most patients, however, and the incidence of side effects is relatively low. 

Drugs that block the alpha-1-adrenergic receptor on vascular smooth muscle will promote a decrease in vascular resistance.37,110 Since the total peripheral vas- 

Alpha-1 blockers can also be used to treat the symptoms of benign prostatic hypertrophy because they decrease sympathetic-mediated contraction of smooth muscle located in the prostate gland.34,91 Reduction of muscle tone in the prostate decreases constriction of the ureter, thereby improving urinary flow and the ability to empty the bladder.58,83 

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ACE inhibitors - AT antagonists - Alpha blockers - Beta blockers Isolated syslolic hypertension (older patienls) - Diuretics preferred (generally Thiazides) - Long-acting dihydropyridine calcium channel blocker... 

The answer is b. (tlardman, p 229. Katzung, p 168.) Terazosin blocks a receptors in arterioles and venules It is 0 -selective. Perhaps this selectivity permits NE to exert unopposed negative feedback on its own release because of little or no effect on presynaptic a.2 receptors. Alpha blockers reduce arterial pressure in both resistance and capacitance vessels andT thereforet are quite effective in reducing blood pressure when a patient is in the upright position... 

Mohan, A.K. et al., Drug-induced systemic lupus erythematosus and TNF-alpha blockers, Lancet 360,646, 2002. 

Alfuzosin is a selective alpha-blocker, which relaxes smooth muscle, thereby increasing urinary flow rate. Because of its alpha-blockade effect, alfuzosin tends to lower the blood pressure and the first dose of the drug may lead to a hypotensive effect. 

Alfuzosin is a selective alpha -blocker, which relaxes the smooth muscle in benign prostatic hyperplasia and hence increases the urinary outflow. 

Alpha-blockers tend to cause vasodilation leading to hypotension especially after the first dose. Subsequently patients on alpha-blockers are advised to take the first dose at night before retiring to bed. Alpha-blockers also tend to cause drowsiness so patients are advised to be careful when driving. 

Terazosin is an alpha-adrenoreceptor blocker that causes vasodilation and is used in the management of hypertension and benign prostatic hypertrophy. Beta-blockers and alpha-blockers can interact to induce hypotension since both act to reduce the blood pressure. Patients already on beta-blockers and who are started on alpha-blockers such as terazosin should be advised to take the terazosin dose at night to reduce the implications (falls) of first-dose hypotension. 

Finasteride can be administered alone or in combination with the alpha-blocker doxazosin. 

Diuretics or beta blockers-- 2. ACE inhibitors, calcium blockers, alpha-] blockers, alpha-beta blocker ... 

Calcium channel blockers, ACE inhibitors, labetalol, and alpha-f blockers -Calcium channel blockers, ACE inhibitors, labetalol, and alpha blockers may... 

Concomitant use with alpha-blockers Do not take 50 or 100 mg doses of sildenafil within 4 hours of alpha-blocker administration. A 25 mg dose of sildenafil may be taken at any time. 

Flypersensitivity to any component of the tablet administration with nitrates (either regularly and/or intermittently) and nitric oxide donors because of the potentiation of hypotension (see Drug Interactions) coadministration with alpha-blockers (vardenafil only) coadministration with alpha-blockers other than 0.4 mg/day tamsulosin (tadalafil only). 

Drugs that may be affected by PDE5 inhibitors include alpha-blockers, amlodipine, angiotensin II receptor blockers, bendroflumethiazide, enalaphl, metoprolol, nifedipine, nitrates, protease inhibitors. 

ALLHAT Authors/Officers and Coordinators. Diuretic versus alpha-blocker as first-step antihypertensive therapy final results from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). Hypertension 2003 42 239-46. 

Parra D, Lnndy AL, Bierman B. Alpha-blocker monotherapy and anticipated occurrences of heart failure in hypertensive veterans. Am J Hypertens 2005 18 573-5. 

General note In resistant (refractory) hypertension centrally acting agents (selective and non-selective) and alpha-blockers may be required to control BR... 

Deficiency of adrenal medullary catecholamines appears to give no ill effects, and replacement therapy is therefore not used, but adrenal medullary tumours, phaeochromocytomas, secrete excess catecholamines often causing hypertension with dramatic episodes of headache, palpitations, pallor, sweating and anxiety. This condition is normally treated surgically, but preoperative preparation is mandatory to avoid catastrophic effects of surges of catecholamine release. A combination of alpha- and beta-adrenergic receptor blockade is normally used, with drugs such as phenoxybenzamine or doxazosin as alpha-blockers, and propranolol as a non-selective beta-blocker. 

SR014 Debruyne, F., G. Koch, P. Boyle, et al., and the Groupe d etude PERMAL. Comparison of a phytotherapeutic agent (Permixon) with an alpha-blocker (Tamsulosin) in the treatment of benign prostatic hyperplasia a 1 -year randomized international study. Prog Urol 2002 12(3) 384-392. 

Geriatric Considerations - Summary Alpha-adrenergic blockers are modestly effective alone, and in combination with 5-alpha reductase inhibitors (e,g, finasteride) in the treatment of urinary obstructive symptoms related to benign prostatic hyperplasia. Alfuzosin is a "uroselective" alpha-blockerwhich appears to cause less orthostatic hypotension than nonselective alpha-blockers such as terazosin, prazosin, and doxazosin. 

Adjunct to alpha-blocking agents to treat pheochromocytoma PO 60 mg/day in divided doses with alpha-blocker for 3 days before surgery. Maintenance (inoperable tumor) 30 mg/day with alpha-blocker. 

Avoid faking sildenafil wifhin 4 hr of an alpha-blocker... 

Alfuzosin (Uroxatral)—another alpha,-blocker for benign prostatic hyperplasia. Med Lett Drugs Ther 2004 46 1-2. 

Alpha blockers are the drugs which block the pressor response to noradrenaline and... 

Positive inotropic and chronotropic effects of catecholamines are not blocked by alpha blockers, but these drugs can block catecholamine induced cardiac arrhythmias. 

Certain stimulant actions of catecholamines on various smooth muscles are blocked by alpha blockers such as uterine contraction of certain species, contraction of vas deferens and retractor penis, stimulation of seminal vesicles and vas deferens. Alpha blockers can inhibit ejaculation and produce impotence. Salivary secretion and sweat formation induced by catecholamines is blocked by alpha blockers. 

Alpha blockers also produce certain metabolic effects such as inhibitory action of adrenaline on insulin secretion is blocked and adrenaline induced rise in blood potassium level is also blocked. 

Miosis and nasal stuffiness can occur with alpha blockers by acting on radial muscles of iris and nasal blood vessels. Diarrhoea may occur due to increase in intestinal motility. 

The common adverse effects with alpha blockers are palpitation, nasal stuffiness, postural hypotension, retention of fluid, diarrhoea, inhibition of ejaculation and impotence. 

Phentolamine, another alpha blocker is exclusively used for the diagnosis of pheochromocytoma and for the prevention of abrupt rise in blood pressure during surgical removal of adrenal medulla tumors. 

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