Pharmacology I: ANS IV - Adrenoreceptor antagonists

…: block impulse transmission at adrenergic neurons or adrenergic receptor sites

adrenoreceptor antagonists (sympatholytics)

Subtypes of adrenoreceptor antagonists: … (2)

alpha-adrenergic blockers, beta-adrenergic blockers

…: prevent the action of NE and E at the a receptor, interfere with synthesis, storage, release and reuptake of NE in neurons

Alpha blockers

Receptor selectivity of  phenoxybenzamine and phentolamine: … (2)

a1, a2

The rest of alpha blockers target …

a1

Effects of alpha blockers: … (4)

decrease TPR, decrease mean BP, reflex tachycardia, water retention

…: irreversible used preoperatively to prevent catecholamine crisis

phenoxybenzamine

…: reversible, given to patients on MAO inhibitors who eat tyramine-containing foods and for sever cocaine -induced hypertension

phentolamine

Adverse effects of nonselective alpha blockers: … (2)

orthostatic hypotension, reflex tachycardia

Used to treat benign prostatic hypertension: … (4)

prazosin, terazosin, doxazosin, tamsulosin

…: treatment for PTSD

prazosin

All a1 selective alpha blockers can be used to treat hypertension except: …

tamsulosin

adverse effects of A1 selective alpha blockers: … (3)

first dose orthostatic hypotension, dizziness, headache

…: inhibit the action of catecholamines at beta receptors, end in -olol (1st gen are non-selective, 2nd gen are B1-selective, 3rd gen are a and B)

Beta blockers

1st gen - Non-selective β-blockers respiratory effects: … (2)

bronchospasm, vasospasm

1st gen - Non-selective β-blockers effects on eye: …

decreased aqueous humor production

1st gen - Non-selective β-blockers metabolic effects: … (3)

decreased glycogenolysis, gluconeogenesis, deceased lipolysis

2nd gen - β1-selective blockers (cardioselectivity): … (5)

decreased HR, contractility, CO, renin release, AV conduction velocity

… (2): used in congestive heart failure and in hypertensive emergencies (3rd gen (combined α-1 and β-blocking activity))

Labetalol, carvedilol

…: some drugs act as partial agonists (pindolol), less bradycardia (resulting from B1 blockers), slight vasodilation or bronchodilation (from B2 activity), minimal change in plasma lipids (B3)

intrinsic sympathommetic acitvity

Beta-blockers are should be used with caution* in … or patients with respiratory disorders and diabetes.

asthmatic patients

Beta blockers adverse effects: … (6)

bronchospasm. bradycardia, hypotension, atrioventricular block, heart failur, respiratory distress