β2-selective agents
Butaxamine
ICI-118,551

β3-selective agents
SR 59230A

β1 selective antagonist and β3 agonist agents
Nebivolol

Comparative information
Pharmacological differences
Agents with intrinsic sympathomimetic action (ISA)
Acebutolol, pindolol, labetalol, mepindolol, oxprenolol, celiprolol, penbutolol
Agents organized by lipid solubility (lipophilicity)High lipophilicity: propranolol, labetalol
Intermediate lipophilicity: metoprolol, bisoprolol, carvedilol, acebutolol, timolol, pindolol
Low lipophilicity (also known as hydrophilic beta blockers): atenolol, nadolol, and sotalol
Agents with membrane stabilizing effectCarvedilol, propranolol > oxprenolol > labetalol, metoprolol, timolol

Indication differences
Agents specifically labeled for cardiac arrhythmia
Esmolol, sotalol, landiolol (Japan)
Agents specifically labeled for congestive heart failureBisoprolol, carvedilol, sustained-release metoprolol
Agents specifically labeled for glaucoma
Betaxolol, carteolol, levobunolol, timolol, metipranolol
Agents specifically labeled for myocardial infarctionAtenolol, metoprolol (immediate release), propranolol (immediate release), timolol, carvedilol (after left ventricular dysfunction), bisoprolol (preventive treatment before and primary treatment after heart attacks)
Agents specifically labeled for migraine prophylaxisTimolol, propranololPropranolol is the only agent indicated for the control of tremor, portal hypertension, and esophageal variceal bleeding, and used in conjunction with α-blocker therapy in phaeochromocytoma. Other effects
Beta blockers, due to their antagonism at beta-1 adrenergic receptors, inhibit both the synthesis of new melatonin and its secretion by the pineal gland. The neuropsychiatric side effects of some beta blockers (e.g. sleep disruption, insomnia) may be due to this effect.Some pre-clinical and clinical research suggests that some beta blockers may be beneficial for cancer treatment. However, other studies do not show a correlation between cancer survival and beta blocker usage. Also, a 2017 meta-analysis failed to show any benefit for the use of beta blockers in breast cancer.Beta blockers have also been used for the treatment of schizoid personality disorder.
Beta blockers, also spelled β-blockers, are a class of medications that are predominantly used to manage abnormal heart rhythms, and to protect the heart from a second heart attack after a first heart attack (secondary prevention). They are also widely used to treat high blood pressure, although they are no longer the first choice for initial treatment of most patients.Beta blockers are competitive antagonists that block the receptor sites for the endogenous catecholamines epinephrine (adrenaline) and norepinephrine (noradrenaline) on adrenergic beta receptors, of the sympathetic nervous system, which mediates the fight-or-flight response. Some block activation of all types of β-adrenergic receptors and others are selective for one of the three known types of beta receptors, designated β1, β2 and β3 receptors. β1-adrenergic receptors are located mainly in the heart and in the kidneys. β2-adrenergic receptors are located mainly in the lungs, gastrointestinal tract, liver, uterus, vascular smooth muscle, and skeletal muscle. β3-adrenergic receptors are located in fat cells.Beta receptors are found on cells of the heart muscles, smooth muscles, airways, arteries, kidneys, and other tissues that are part of the sympathetic nervous system and lead to stress responses, especially when they are stimulated by epinephrine (adrenaline). Beta blockers interfere with the binding to the receptor of epinephrine and other stress hormones and weaken the effects of stress hormones.