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Author: Admin | 2025-04-28
Failure — carvedilol, metoprolol and bisoprolol.Different Classes of Beta-Blockers and Specific DrugsBeta-blockers that are used clinically can be divided into two classes: 1) non-selective blockers (block both β1 and β2 receptors), or 2) relatively selective β1 blockers ("cardioselective" beta-blockers). Some beta-blockers have additional mechanisms besides beta-blockade that contribute to their unique pharmacologic profile. The two classes of beta-blockers along with specific compounds are listed in the following table. The clinical uses indicated in the table represent both on and off-label uses of beta-blockers. For example, a beta-blocker may only be approved by the FDA for treatment of hypertension; however, physicians sometimes elect to prescribe the drug for angina because of the class-action benefit that beta-blockers have for angina. Clinical UsesClass/DrugHTNAnginaArrhyMICHFNon-selective β1/β2 carvedilolX XMSA; additional alpha-blocking activitylabetalolXX ISA; MSA; additional alpha-blocking activitynadololXXXX long actingpenbutololXX ISApindololXX ISA; MSApropranololXXXX MSA; prototypical beta-blockersotalol X several other significant mechanismstimololXXXX primarily used for glaucomaClass/DrugHTNAnginaArrhyMICHFβ1-selective acebutololXXX ISA; MSAatenololXXXX betaxololXXX MSAbisoprololXXX X esmololX X ultra-short acting; surgical and post-surgical HTNmetoprololXXXXX nebivololX relatively selective in most patients; vasodilating (stimulates NO release)Class/DrugHTNAnginaArrhyMICHFAbbreviations: HTN, hypertension; Arrhy, arrhythmias; MI, myocardial infarction; CHF, congestive heart failure; ISA, intrinsic sympathomimetic activity; NO, nitric oxide.Side Effects and ContraindicationsCardiovascular side effectsMany of the side effects of beta-blockers are related to their cardiac mechanisms and include bradycardia, reduced exercise capacity, heart failure, hypotension, and atrioventricular (AV) nodal conduction block. Beta-blockers are therefore contraindicated in patients with sinus bradycardia and partial AV block. The side effects listed above result from excessive blockade of normal sympathetic influences on the heart. Considerable care needs to be exercised if a beta-blocker is given with cardiac selective calcium-channel blockers (e.g., verapamil) because of their additive effects in producing electrical and mechanical depression. Although this may change with future clinical trials on safety and efficacy of beta-blockers in heart failure, at present only
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