Adrenergic 2 Flashcards
NON-SELECTIVE alpha ADRENERGIC BLOCKERS?
- PHENOXYBENZAMINE
* PHENTOLAMINE
Uses of Phenoxybenzamine?
• Irreversible antagonist. • Unsuccessful for hypertension. • Used in Pheochromocytoma • Prior to surgical removal of the tumor. • For chronic management of inoperable tumors.
Uses of Phentolamine?
Reversibly blocks alpha 1 and alpha 2 receptors.
• Pheochromocytoma: control of hypertension
during preoperative preparation and surgical
excision.
• Diagnosis of pheochromocytoma: phentolamine
blocking test.
• Prevention of dermal necrosis after extravasation
of norepinephrine.
• Hypertensive crisis due to stimulant drug
overdose.
What are the alpha 2 selective adrenergic blockers?
PRAZOSIN
TERAZOSIN
DOXAZOSIN
TAMSULOSIN
What are the alpha 2 selective adrenergic blockers uses? CV effect?
treatment of Htn(Not DOC), prazosin is the prototype.
• Lower arterial blood pressure by relaxing both
arterial and venous smooth muscle.
• First dose produces an exaggerated
hypotensive response that can result in syncope
(fainting).
• The first dose must be 1/3 or 1/4 of normal
dose.
BPH
• DOC for symptom relief.
• Relax smooth muscle in the bladder neck,
prostate capsule and prostatic urethra improving
urinary flow.
Tamsulosin selective for which receptor? Uses?
• Three subtypes of the α1 -receptor: α1A , α1B , α1D . • The α1A -receptor predominates in GU smooth muscle. • Tamsulosin is selective for α1A -receptors. • Approved for BPH. • Little effect on blood pressure. • Less likely to cause orthostatic hypotension.
TERAZOSIN & DOXAZOSIN uses and pharmokinetic difference from prazosin?
- Prazosin analogs with longer half-life.
* Used for hypertension and BPH.
What are the Non selective Beta blockers?
PROPRANOLOL (The prototype)
NADOLOL
TIMOLOL
Effects: slow heart rate and decrease myocardial contractility
• Nonselective β blockers are contraindicated
in patients with asthma.
decreasd glycogenolysis and glucagon secretion
ATENOLOL & METOPROLOL uses?
Beta 1 selective adrenergic antagonists
• Useful in hypertensive patients with impaired
pulmonary function.
• Useful in diabetic hypertensive patients who are receiving insulin or oral hypoglycemic agents
Esmolol uses and pk, roa?
Beta 1 selective adrenergic antagonists
• Ultra-short acting
• Half life ̴10 minutes
• Given IV
• For rapid control of ventricular rate in patients
with atrial fibrillation or atrial flutter.
CARVEDILOL uses?
- Similar to labetalol.
- Has antioxidant properties.
- Used in hypertension and CHF.
LABETALOL uses and moa?
- Competitive antagonist at betaand alpha 1 receptors.
- More potent as a beta-antagonist than as an αantagonist.
- Used in hypertension.
Pindol use?
PARTIAL beta-AGONIST
• May be preferred in individuals with diminished
cardiac reserve or a propensity to bradycardia.
What are all of beta blocker uses?
Performance Anxiety (“Stage Fright”) • β-blockers are the preferred treatments.
MI
• beta-blockers have a protective effect on the
myocardium.
Atrial Fibrillation
• beta-blockers are indicated to control ventricular
rate.
Angina Pectoris
• beta -blockers decrease O2 requirement of heart
muscle.
• Useful in chronic management of stable angina.
• Not for acute management
.Hyperthyroidism
• beta-blockers blunt sympathetic stimulation that
occurs in hyperthyroidism.
Glaucoma
• beta-blockers, particularly timolol, are effective in
diminishing intraocular pressure in glaucoma.
Migraine
• beta-blockers are effective for prophylaxis of
migraine.
Hypertension
• beta-blockers lower blood pressure in hypertension
by decreasing cardiac output
Essential Tremor
• Essential tremor is the most common neurologic
cause of postural or action tremor.
• β- blockers are the most commonly used drugs
for the treatment of essential tremor.
Beta blocker AE
Bronchoconstriction
• Nonselective beta-blockers: Potentially lethal side
effect in asthmatics.
• beta1-selective drugs may be less likely to
evoke bronchospasm.
• The selectivity of beta blockers for beta1 receptors
is modest: they should be avoided if at all
possible in patients with asthma.
Hypoglycemia
• Nonselective beta-blockers may impair recovery
from hypoglycemia in insulin-dependent diabetics.
Due to blockade of beta2 receptors in the liver.
• Also, they mask the tachycardia typically seen
with hypoglycemia, denying the patient an
important warning sign.
• A beta1-selective blocker is preferable.
Lipid metabolism
• Blockade of beta receptors inhibits release of free
fatty acids from adipose tissue.
• Both non-selective and β1-selective blockers
increase TG and reduce HDL.
• Lipid levels are relatively unaffected by labetalol
and partial agonists like pindolol.
CNS effects: sedation, dizziness, lethargy, fatigue
