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19 Cards in this Set
- Front
- Back
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Nonselective alpha anatagonists
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Phenoxybenzamine a1>/=a2(ergot alkaloids, enuroleptics, tricyclic antidepressants) a1>>a2
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alpha 1 selective antagonists
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prazosin and tramsulosin
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alpha 2 selective antags
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yohimbine
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beta nonselective anatags
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propanolol, pindolol, timolol, sotalol
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beta 1 selective anatags
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metoprolol, atenolol, esmolol
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beta 2 selective antags
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butoxamine
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alpha1, beta1,2 antags
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labetalol and carvedilol b1=b2>/=a1
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inhib of catecholamine synthesis
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metyrosine
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mechanism of action of alpha receptor antags
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1. irreversibly block alpha receptors
2.reversibly block alpha receptors (all but phenoxybenzamine) -can be selective or non selective |
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pharm of nonselective alpha antags
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-increase HR, vasodilate, impaired response to catecholamines, contraction of smooth muscle
-long duration of action -potential to inhibit catecholamine reuptake and irreversibly block M, 5HT, and histamine receptors -30% oral availability, half life 24 hr, disperse to ALL tissues |
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pharm of alpha 1 antags
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-selective, competitive blockade of a1 and inhib of phosphodiesterase in high doses
-vasodilation, slight increase in contractility of heart, catecholamine responses are impaired, -large oral avail,total dist, large metab in liver, praz has short half life but dox longer |
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adverse effects and contraindications of alpha antags
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-posthural hypertension, "first-dose phenomenon", tachy, palpitations, arrythmias, nasal stuffiness, peripheral edema, fatigue, dizziness, headache, nausea, urinary incontinence, sexual dys, skin rashes
-urge incontinence, exertional anginal, postural hypertension |
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therapeutic uses of alpha antags
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-pheochromocytoma (beta blockers needed AFTER alpha blockers)
-urological problems -peripheral vascular disease -chronic hypertension/hypertensive emergencies -heart failure -sympathetic dystrophy and causalgia |
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pharm of beta antags
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-lower CO, conduction, and automaticity
-increase myocardial perfusion but lower cardiac O2 demand -decrease bo -bronchioconstriction in pts with asthma or COPD -decreased production of aq humor and slight contractin of ciliary muscles -decreased renin, symp-mediated lipolysis and liver glycogenolysis, increase in VLDL, decrease K uptake by skeletal muscle |
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alpha-beta antags
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-marked decrease in TPR
-minimal changes in HR and CO at rest |
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beta antag pharmacokinetics
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-lipid solubility!-most lipiophillic have low bioavail, marked 1st pass, large VD, easy crossing of BBB, high metab clearance, intermediate half-life
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adverse effects of beta-antags
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-peripheral vascular problems, brady, heart failure, withdrawals, asthenia, insomnia, dizziness, nightmares, hallucinations, psychic depression, anorexia, nausea, vomiting, diarrhea, increased airway restriction, sexual dys in males, hypoglycemic reactions, hypertensive crisis, hyperkalemia, skin rashes and agranulocytosis
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therapeutic uses of beta blockers
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-hypertension, cardiac arrythmias, exertional angina,
-open amgle glaucoma, hyperthyroidism, acute MI, chronic coronary insufficiency, hypertrophic cardiomyopathy, chronic heart failure, termor, pheochromocytoma, migranes, prevention of esophageal varices, anxiety/panic |
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Metyrosine
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-indirect acting antiadrenergic
-inhibs tyrosine hydroxylase, rate limiting enzyme in catecholamine synthesis -adverse:postural hypotension, diarrhea, sedation, psychic distrubrances -uded in preop pts with pheochromocytoma or to maintain the inoperable |
