Term
| mechanism of action for b blockers |
|
Definition
-competitively block the effects of endogenous ne and epi and b receptors
-inhibits the normal sympathetic effects:
-inc HR and force of contractility
-bronchodilation
-vasodilation
-relax. of smooth muscle
-hepatic glycogenolysis
-lipolysis |
|
|
Term
| intrinsic sympathomimetic activity |
|
Definition
-ability of b blocker to stimulate b adrenergic rs weakly
-provide some background of symp. act. while preventing normal and enhanced act
-inhibit act. of b rs when sns is stim. due to stress/excer. in presence of high conc of epi and ne
-useful in pts who become bradycardic or develop bronchoconstriction while on full agonists |
|
|
Term
| membrane stabilizing activity (MSA) |
|
Definition
-blocks myocyte na chs.
-prevents proper cardiac conduction
-no therapeutic role HTN
-seizures are observed at toxic doses
-b blockers w/msa are associated with largest proportion of fatalities at toxic doses |
|
|
Term
|
Definition
-inter-patient variability
-drug-drug interactions
-cns side effects
-rapid 1st pass metabolism
-low bioavai. due to wide distribution
-crosses BBB |
|
|
Term
|
Definition
-not much inter-pt variability
-less drug-drug interactions
-less cns effects
-excreted unchanged renally by liver and kidneys
-doesnt cross BBB
-longer elimination half lives |
|
|
Term
| therapeutic indications of b blockers |
|
Definition
-htn
-angina
-post MI
-arrhythmias (ventricular tachycardia and atrial fibrillation)
-heart failure
-benign essential tremor, performance anxiety, migraine prophylaxis, pheochromocytoma w a blocker |
|
|
Term
|
Definition
-1st generation of b blockers
-bind to b1 and b2 rs
-cns side effects most common |
|
|
Term
|
Definition
-nonselective
-1st clinically active b blocker
-lipophilic
-iv and po |
|
|
Term
|
Definition
|
|
Term
|
Definition
-nonselective
-used for open angle glaucoma
-PO, ophthalmic soln, gel-forming soln |
|
|
Term
|
Definition
-cardioselective is NOT associated with a dif. in BP lowering-effect
-ALL b blockers are nonselective at high doses |
|
|
Term
|
Definition
-b1 sel.
-ISA and MSA
-hydrophilic
-PO only |
|
|
Term
|
Definition
-b1 sel.
-excreted largely unchanged
-caution in pts with reduced renal func.
-PO only |
|
|
Term
|
Definition
-b1 selective
-1 of the most potent and
cardioselective of b blockers
-preferred for pts with bronchospastic pulmonary disease
-HTN, glaucoma, ocular HTN
-PO and ophthalmic |
|
|
Term
|
Definition
|
|
Term
|
Definition
-b1 sel.
-ER setting bc short half-life (9 mins)
-continuous IV |
|
|
Term
| metoprolol (toprol, lopressor) |
|
Definition
|
|
Term
|
Definition
-the most b1 selective agent
-vasodilatory properties due to NO modulation
-PO only |
|
|
Term
| labetalol (normodyne, trandate) |
|
Definition
-antagonist at b1, b2, a1
-PO and IV |
|
|
Term
|
Definition
-antagonist at b1, b2, a1
-PO only |
|
|
