Beta-Adrenergic Antagonists/Blockers

What acts on the beta receptors?

norepinephrine

location of beta receptors in the heart

- SA node

- AV node

- atria

- ventricles

physiologic effects in the heart

- ↑ heart rate (chronotropy)

- ↑ contractility (inotropy)

- ↑ automaticity and conduction velocity

location of beta receptors in the vasculature

- coronary

- skin

- mucosa

- skeletal muscle

- cerebral

- pulmonary

- abdominal viscera

- renal

physiologic effects in the vasculature

vasodilation

location of beta receptors in the lungs

- tracheal

- bronchial smooth muscle

physiologic effects in the lungs

bronchodilation

location of beta receptors in the kidneys

juxtaglomerular cells

physiologic effects in the kidneys

↑ renin release

cardioselective antagonists

- metoprolol

- atenolol

- nebivolol

- bisoprolol

- acebutolol

- betaxolol

- esmolol

What are cardioselective antagonists selective for?

beta1-selective

nonselective antagonists

- nadolol

- propranolol

- penbutolol

- pindolol

- sotalol

- timolol

mixed antagonists

- carvedilol

- labetalol

Which cardioselective antagonist has vasodilatory activity via nitric oxide production?

nebivolol

Which beta-adrenergic antagonists are partial agonsists?

- acebutolol

- penbutolol

- pindolol

- labetalol

What nonselective antagonist is primarily used for its anti-arrhythmic activity?

sotalol

How to reduce risk of hypotension while using carvedilol?

take with meals

Which drugs are available as IV formulations?

- esmolol

- metoprolol

- propranolol

Which drugs have an extended-release formualtion?

- carvedilol

- metoprolol

- propranolol

Which beta-blockers are NOT cleared through the liver?

- atenolol

- nadolol

- sotalol

How can beta-blockers cross the Blood-Brain Barrier?

having high lipophilicity

Which drug is cleared through RBC esterases?

esmolol

Which drug is used for CNS indications?

propranolol

adverse reactions

- bradyarrhythmias

- bronchospasm

- fatigue, insomnia, sleep disturbance

- hypotension

- masking of hypoglycemia

- metabolic: ↑ total cholesterol, ↑ triglycerides

- sexual dysfunction

- withdrawal syndrome with abrupt discontinuation: rebound tachycardia, rebound hypertension, ischemia

Which drugs go through CYP2D6 metabolic pathway?

- carvedilol

- metoprolol

- propranolol

Which drug is preferred in pregnant patients?

labetalol

key monitoring parameters

- BP

- HR

- evidence of CNS impairment

- signs and symptoms of bronchospasm in patients with preexisting airway disease

- renal function in those on renally cleared beta-blockers

- blood glucose in patients with diabetes

safe use of beta blockers (class purposes)

- do not initiate a beta-blocker if HR