Pharm 10.2 Flashcards
selective Beta 1 blockers
Acebutolol, atenolol, metoprolol
betablockers - ISA - intrinsic sympathomimmetic activity
Acebutolol, Pindolol
beta blockers with sedation effects
most except Atenolol
beta blockers that increase blood lipids
most except Acebutolol and Pindolol
Propanolol administration
oral is well absorbed, undergoes extensive first pass metabolism
Propanolol and BBB
Propranolol is lipophilic so it inters the BBB
Propanolol excretion
excreted in urine as glucuronide metabolites
nonselective beta blockers on inotropy
dec force of contration - negative inotropy
nonselective beta blockers on chronotropy
dec rate of contraction - negative chronotropy
nonselective beta blockers on SA and AV nodes
supress SA and AV nodal activity – bradycardia
overall effect of beta blockers on the heart
dec heartrate, SV, and CO, decBP in hypertensiv ppl –>reflex peripheral vasoconstriction
Why is Propranolol useful in angina
dec cardiac work so dec O2 consumption
Propranolol on blood vessels
blocks B2 mediate vasodialation
nonselective beta blockers and BP
does not dec BP in normal ppl, but decreases BP in hypertensive ppl (both systolic and diastolic)
nonselective beta blockers and postural hypotension
no postural hypotension because no effect on alpha 1 adrenergic receptors
Propranolol and the Kidney
decrease renin release from kidney (beta 1 action) – very useful property in reducing compensatory BP elevation
beta blockers are often combined with
a diuretic in treatment of HTN
Propranolol and respiratory tract
bronchoconstriction and can precipitate bronchial asthma (Beta 2 action)
Beta 2 blocker contraindications
bronchial asthma
beta blockers and the eyes
dec IOT due to inc aqueous humor production
Propranolol and the CNS
sedation, lethargy, depression, forgetfulness, sleep disturbances (dreams and nightmares) worse in lipophilic agents
Propranolol and skeletal muscle
antaganizes the epinephrine induced tremmors (muscle spindle controling tremors is under beta 2 control)
Propranolol metabolic effects
blocks epinephrine induced glycogenolysis –> fasting hypoglycemia; decrease insuline release (beta 2 block) after meal causing hyperglycemia
why should propranolol be used with caution in diabetics
bc it masks the warning sympathetic signes and symptoms such as swating, palpitations (tachycardia) induced by hypoglycemia
what is a warning sign of hypoglycemia
tachycardia –this is masked by beta blockers
therapeutic uses of Propranolol
hypertension, Angina (except Prinzmetal’s angina), MI (prophylactic use post-MI), Cardiac arrhythmias (Class II: Propranolol, Acebutolol, Esmolol), Migraine (prophylactically), Hyperthyroidism, Pheochromocytoma, Performance anxiety, Essential tremors, Glaucoma (Timolol), CHF, Hypertrophic cardiomyopathy, marfan syndrome and aneurysms
Beta blockers and hyperthyroidism
chance of thyroid storm increases during surgical removal of theyroid so betablockers beore surgery is desirable
CHF and beta blockers
dec sympathetic discharge and NE release dec CHF mortality
hypertrophic cardiomyopathy and betablockers
dec syncope, arrhythmias, and sudden death
Marfan syndrome and aneurysms and betablockers
alone or combined with ACEI/ARB dec aneurismal dialation by dec TGFbeta activity
beta blocker adverse CVS effects
bradycardia, AV block, abrupt discontinuation of propranolol can precipitate angina, arrhythmia, and hypertension —should be withdrwan gradually after long term use
beta blockers adverse respiratory effects
causes bronchoconstriction, should not be used in asthmatic and COPD patients
beta blockers adverse metabolic effects
fasting hypoglycemia, increases blood lipid levels (LDLs and TGs)
beta blockers and other adverse effects
sexual dysfunction, fatigue and exercise intolerance
betablockers are contraindicated in
asthmatics, COPD, diabetics, Raynaud’s disease, Prinzmetal angina
beta blockers with Digitalis and verapamil
additive depression of SA and AV node –> cardiac arrest
beta blockers and insuline/oral hypoglycemics
aggravate hypglycemic effects, mask warning signes (tremor and tachycardia)
betablockers and indomethacin and other NSAIDs
annul antihypertensive actions of betablockers
betablockers and cimetidine
inhibits metabolism of Propranolol
Timolol
potent nonselective betablocker, reduces the production of aqueous humor in the eye and hence used topically for the treatment of chronic open-angle glaucoma
nadolol
very long duration, same actions as propranolol (nonselective)
selective beta 1 antagonists
acebutolol, atenolol, esmolol, metoprolol
selective beta 1 antagonists can be used
in hypertensive patients with asthma and COPD bc they do not cause bronchoconstriction at therapeutic doses
selective beta 1 antagonists actions
decrease BP in hypertensive pts, inc exercise tolerance in angina, no bronchoconstriction effect, no effect on PR, no effect on CHO metabolism
therapeutic uses of beta 1 blockers
HTN (esp if they have pulm dysfuntion or diabetes), Angina, MI
beta1 blocker adverse effects
bradycardia
Atenolol
selective beta 1 blocker
Atenolol properties
lower lipid solubility, less CNS entry, excreted unchanged in the urine
Atenolol uses
HTN, Angina, MI
Metoprolol administered
orally/ IV for HTN, Angina, MI
Vasodialating beta blockers (less adverse effects)
labetalol, carvedilol, nevibolol, celiprolol
labetalol
beta blocker with additional alpha 1 blockade
carvedilol
nonselective beta blocker, alpha 1 blocker, ca-channel blocker, antioxidant
carvedilol halflife
7 hours
Nevibolol
cardioselective, anti-oxidant, beta 3 sitmulation causing NO production (effective in black ppl)
Celiprolol
Cardioselective, beta 1 blocker, beta 2 agonist, NO production
betablocker responsivness and ethnicity
chinese>white>black
American SNP asscociated with better survival in CHF patients treated with beta blockers
ADRB1gly389gly > ARDB1arg389gly
Esmolol
shortest acting beta 1 blocker, IV administration to treat acute supraventricular tachycardia
beta 1 blockers with ISA
pindolol, acebutolol
beta1 blockers with ISA cause
less bradycardia (beta1) and slight vasodialation or bronchodialation (beta2), act partial agonists
beta 1 blockers with ISA uses
HTN with moderate bradycardia in DM , CHO metabolism is less affected
beta blocker with K+ channel block
sotalol - used as antiarrhythmic (class 3)
alpha and beta blockers
labetalol, carvedilol
actions of Labetalol and carvedilol
peripheral vasodialation dec BP – used in HTN emergency
benefits of labetolol and carvedilol
does not cause reflex bradycardia
cons of labetolol and carvedilol
same contraindications as nonselective beta blockers