Alpha 1 blockers:

{doxazosin, terazosin, prazosin}

-- act peripherally
--causes vasodilation of both arteries and veins (indirect vasodilator)
--causes less reflex tachycardia than direct vasodilators (hydralazine/minoxidil)

--side effects: dizziness, priapism, orthostatic hypotension, first dose syncope, peripheral edema

--drug drug interaction: NSAIDs can decrease antihypertensive properties of alpha 1 blockers

Alpha 2 agonists

{clonidine, guanfacine, methyldopa}

-- act centrally
--decrease sympathetic outflow to CV system

--side effects: sedation, dry mouth, bradycardia, withdrawal hypertension, orthostatic hypotension, depression, impotence, sleep disturbances


Beta Blockers

{atenolol, etc.}

--beta 1 = heart
--beta 2 = kidney, lungs, periphery

--used for lots of things: HTN, migraines, essential tremor, anxiety, hyperthyroidism, stage-fright, glaucoma

--blocks secretion of renin (renin is an enzyme secreted by kidney that is a potent vasoconstrictor)
--decreases contractility thus decreasing cardiac output
--decreases heart rate

-- avoid abrupt withdrawal
--side effects: dizziness, hypotension, sexual dysfunction, bronchospasm, heart failure, bradycardia

-- can increase triglycerides (except those with ISA activity)...seen mainly in non-selective beta blockers. Can also decrease HDL. I read that this is usually not clinically significant.
--can mask signs of insulin-induced hypoglycemia (non-selective beta blockers) that are associated with epinephrine release (palpitations, tremor, hunger) but they do not mask the sweating.
--can also inhibit insulin secretion and cause hyperglycemia in some pts

-- High lipid solubility = enters CNS more than hydrophilic....Propranolol has high lipid solubility so that is why it is used over other beta blockers for migraine prophylaxis.

ISA (intrinsic sympathomimetc activity)
--only partially stimulate the receptor. When given to a pt with a slow HR, may increase the HR. When given to a pt with a fast HR, may slow it.
--less likely to cause bracycardia, bronchospasm, reduced cardiac output, and increased triglycerides
Acebutolol (Sectral)
Carteolol (Cartrol)
Penbutolol(Visken)

Beta 1 only (cardioselective)
acebutolol
atenolol
betaxolol
bisoprolol

Combined alpha and beta blockers
Carvedilol (Coreg)
Labetalol (Normodyne, Trandate)