Adrenergic Agonists And Antagonists 2 Flashcards
(48 cards)
Low dose of epinephrine mainly causes ______
Vasodilation due to β2 activation;
High doses: both α1 and β2 activated but vasoconstriction due to α1 > β2
Changes in _______ will produce a secondary homeostatic response that tends to compensate for any changes
MAP
What are the 5 classes of drugs that are adrenergic agonists?
- α antagonists: non selective and α1
- β antagonists: non selective and β1
- α1 and β antagonists
- partial agonists
- drugs that act presynaptically
Drugs that are non selective α adrenergic blockers
- phenoxybenzamine
- phentolamine
Phenoxybenzamine and phentolamien are _________
NON selective α adrenergic blockers
MOA of phenoxybenzamine and what is it used for?
Irreversible antagonist and is unsuccessful for treating hypertension
USED IN PHEOCHROMOCYTOMA
What drug would you give to treat pheochromocytoma
Phenoxybenzamine; give it prior to surgical removal of the tumor or if the tumor is inoperable
Phentolamine ______________ blocks __________
Reversibly; α1 and α2 receptors
What are some uses for phentolamine?
- control of HTN during preoperatirve preparing and surgical excision in pheochromocytoma
- used to DIAGNOSE pheochromocytoma via the phentolamine blocking test
- prevention of dermal necrosis due to NE
- solve hypertensive crisis due to stimulant drug overdose
______________ ↓ in response to epinephrine that is given in the presence of phenoxybenzamine
Systemic BP because the α1 action is blocked but NOT the β2 action → vasodilation
What is the clinical implication of someone taking α blockers and then they have a allergic reaction?
Would have to administer epinephrine but instead of ↑ their BP it would ↓ their BP because the β2 would be more activated because all the α receptors are blocked
List the 4 α1 selective adrenergic blockers
- prazosin
- terazosin
- doxazosin
- tamsulosin
What is important about when giving someone α1 blockers for the first time?
The first dose produces an exaggerated hypotensive response so the first dose should be 1/3 or 1/4 of the normal dose
α1 blockers are the drugs of choice for ______
Symptom relief of benign prostatic hyperplasia : relaxes smooth muscle in genitourinary tract improving urinary flow
__________ and __________ of the α1 blockers have longer half life
Terazosin; doxazosin
__________ is the α receptor subtype that is found predominant in the GU smooth muscle and _______ is selective for them
α1A; tamulosin
What are the benefits of using tamulosin?
Treat BPH with less effect on BP and less chance to cause orthostatic HTN because it acts specifically on α1A receptor
What are the non selective β blockers?
- propranolol
- nadolol
- Timolol
Non selective β blockers are contraindicated in _______
Patients with asthma
Metabolic effects of non selective β blockers:
↓ glycogenolysis
↓ glucagon secretion
what are the β1 selective adrenergic antagonists
- atenolol
- metoprolol
- esmolol
What kind of drugs would you give hypertensive patients with impaired pulmonary function
Β1 selective antagonists such as: atenolol and metoprolol
What would you give diabetic hypertensive patients who are using insulin to treat their hypertension
Β1 selective antagonists: atenolol and metoprolol
Esmolol is a _______________ drug and is given via _________ for ___________
Β1 selective antagonist; IV; rapid control of ventricular rate in patients with atrial fibrillation or atrial flutter
