Adrenergics:β adrenergic receptor antagonists Flashcards
Minor actions of B adrenergic recpetor antagonists
partial agonists (i.e., activate β receptors partially in the absence of catecholamines; however, the intrinsic activities of these drugs are much less thana full agonist);
- local anesthetic or quinidine-like activity
- block α1 receptors
- vasodilating properties
Non-Subtype-Selective β Adrenergic Receptor Antagonists known as
(“First Generation”)
Prototype B adrenergic receptor antagonists
Propranolol
Propranolol works by:
Competitive reversible blockade of both β1 and β2 receptors
Propranolol works on B1, B2, both receptors
both
Propranolol is used for:
Hypertension -
Angina -
Certain cardiac arrhythmias due to excess catecholamines or that respond to a
reduction in heart rate/AV conduction velocity
- Acute myocardial infarction
- Pheochromocytoma (adrenal tumor =excess NE
- Migraine prophylaxis
Side effects of propranolol on HR Airway sugars others
Side Effects
- Cardiac depression, bradycardia/heart block
- May increase airway resistance
- Mask symptoms of hypoglycemia
- Sedation, impotence, nightmares
A patient has asthma and congestive heart failure. is propranonolol safe?
Use with caution in patients with:
If a patient has bradyarrhythmias, AV block or hypotension, are we safe to prescribe propranolol?
prescribe propranolol with caution, may exacerbate those
What drug should we be wary of when prescribing heart meds to individual with insulin-dependent diabetes?
Propranolol
insulin-dependent diabetes prone to hypoglycemic episodes
supersensitivity to β adrenergic stimulation which may cause angina, arrhythmias, or infarction could be caused by
Withdrawal syndrome from propranolol
Timolol (Timoptic®) is:
non-selective β receptor antagonist
Therapeutic use of timolol
angina/hypertension/pherochromocytoma/ arrythmias d/t excess catecholamines/ acute myocardial infarction
same as propranolol
widely used in the treatment of wide angle glaucoma
Timolol
How does timolol help with wide angle glaucoma
- decreases aqueous humor formation by ciliary epithelium leading to decreased intraocular pressure