EX2 Beta Blockers (P'col)

Non-selective (First generation)

Nadolol

Propranolol

Timolol

Sotalol

β1-selective (Second generation)

Atenolol

Bisoprolol

Esmolol

Metoprolol

Non-selective (Third generation)

Carvedilol

Labetalol

β1-selective (Third generation)

Nebivolol

Propanolol

NON-SELECTIVE BETA

ANTAGONISTS (FIRST GENERATION)

Timolol

Competitive, reversible antagonist

of β1 and β2 receptors

• Major therapeutic use

• Glaucoma

• Decreases aqueous humor formation

Metoprolol

BETA1-SELECTIVE ANTAGONISTS

(SECOND GENERATION)

Esmolol

BETA1-SELECTIVE ANTAGONISTS

(SECOND GENERATION)

Labetalol

Third gen

• Competitive, reversible antagonist of α1

and both β receptors

• Used to treat:

• Hypertension

• Hypertensive emergencies (IV

administration

Nebivolol

Third gen

Highly selective β1 receptor antagonist

• Also stimulates NO-mediated

vasodilation

• Used to treat:

• Hypertension

Carvedilol

third gen

• Competitive, reversible antagonist of α1

and both β receptors

• Also has antioxidant and anti-

inflammatory properties

• Blocks L-type calcium channels at

higher doses

• Used to treat:

• Heart failure with reduced ejection

fraction

• Hypertension

• Reduces mortality in patients after

myocardial infarction

Clinical use of beta blockers in HTN

Effective and well-tolerated

• No longer a first-line therapy, particularly in patients over

age 60 years

• May be associated with inferior protection against stroke risk

Ischemic heart disease

Blockade of cardiac β receptors results in:

• Decreased cardiac work

• Reduction in oxygen demand

• Reduces the frequency of angina episodes

• Improves exercise tolerance in many patients with angina

• Prolongs survival of patients who have had a myocardial infarction

Strongly indicated in the acute phase of myocardial infarction

Cardiac arrhythmias

Effective in the treatment of both supraventricular and ventricular

arrhythmias

• Slows ventricular response rates to atrial flutter and fibrillation

• Increases atrioventricular nodal refractory period

• Can also reduce ventricular ectopic beats, especially if precipitated by

catecholamines

Esmolol is useful against acute perioperative arrhythmias

• Short duration of action

• Sotalol has antiarrhythmic effects involving ion channel blockade

Heart failure

• Effective in reducing mortality in patients with chronic

heart failure

• Metoprolol, bisoprolol, carvedilol

• Mechanisms are uncertain

• Beneficial effects on myocardial remodeling

• Decreases the risk of sudden death

Glaucoma

• Reduces intraocular pressure

• Reduced production of aqueous humor by the ciliary body

• Open-angle glaucoma

• Comparable efficacy to epinephrine or pilocarpine

• Better tolerated

• Beta blockers that lack local anesthetic properties are suitable for local use in the

eye

Hyperthyroidism

• Beta blockers ameliorate the symptoms of hyperthyroidism

that are caused by increased beta-adrenergic tone

Should be given to most hyperthyroid patients who do not

have a contraindication to their use

Migraine

• Preventative treatment

Established as effective

• Propranolol, metoprolol, timolol

Essential tremor

• Sympathetic activity may

enhance skeletal muscle tremor

• Propranolol

Performance anxiety

• Reduction of the somatic

manifestations of anxiety

• Propranolol

Comorbidities should always be considered

• β1-selective antagonists are preferable in patients with:

Bronchospasm

• Diabetes

• Peripheral vascular disease

• Raynaud’s phenomenon

Cardiovascular ADR

HF

Bradyarrhythmias

Exacerbate peripheral vascular disease

• Raynaud’s phenomenon

• Abrupt discontinuation

• Exacerbate angina

• Increased risk of sudden death

• Exercise intolerance

Pulmonary ADR

Block β2 receptors in bronchial smooth

muscle

• Little effect in normal individuals

• In patients with asthma or COPD, can

cause life-threatening

bronchoconstriction

Less likely with β1-selective antagonists

or β antagonists with ISA

CNS ADR

 Fatigue

• Sleep disturbances (insomnia, nightmares)

• Depression

METABOLIC EFFECTS ADR

Delays recovery from

hypoglycemia

• β2-mediated effects of

catecholamine on gluconeogenesis

and glycogenolysis

• β1-selective antagonists are less

likely to delay recovery from

hypoglycemia

• Blunts the perception of

symptoms of hypoglycemia

• Tremor, tachycardia, nervousness

Can be a problem for older diabetic patients