Term
| these drugs are adrenergic "blocking", but what is the technical term? |
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Definition
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Term
| what is the effect of administering alpha receptor antagonists (blockers)? |
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Definition
| decreased TPR, decreased BP, increased HR/CO (baroreceptor reflex), enhanced norepinephrine release (ineffective due to blocked receptors), orthostatic hyptension (BP suddenly falls when the person stands up, should be covered by efferent side of baroreceptor reflex) |
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Term
| what is the baroreceptor reflex? |
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Definition
| a cardiac negative feedback loop, where decreased blood pressure depresses the baroreflex, causing heart rate and thus blood pressure to rise (and vica versa) |
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Term
| what are the mixed alpha1 and alpha2 blockers? |
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Definition
| phenoxybenzamine and phentolamine |
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Term
| what is the effect of phenoxybenzamine administration? does it bind irreversibly? what is it used for? |
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Definition
| phenoxybenzamine binds irreversibly and causes decreased blood pressure (alpha1), tachycardia (alpha2 - the check on too much NE at the synapse/reduces sympathetic outflow), and it inhibits uptake1 (synaptic catecholamine removal system). it is used for pheochromocytoma tx (tumor of chromafin cells) |
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Term
| what are ADRs for phenoxybenzamine? |
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Definition
| orthostatic/postural hypotension, tachycardia, and inhibition of sperm production/ejaculation |
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Term
| what is the mnemonic for ANS/male sexual function? |
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Definition
Parasympathetic/Point/erection
Sympathetic/Shoot/ejaculation |
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Term
| how does phentolamine compare to phenoxybenzamine? what is it used for? |
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Definition
| phentolamine is exactly the same as phenoxybenzamine and is used for the same tx, but it also causes serotonin and histamine release and does not interfere with male sexual function |
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Term
| what is the general use for alpha1 blockers? what is seen with the first dose? |
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Definition
| reduction of HTN. first dose phenomenon can occur where the pt experiences postural hypotenstion, syncope (dizzy), but tolerance to these effects will develop |
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Term
| what are the alpha1 blockers? what do they end in? |
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Definition
| prazosin, terazosin, and doxazosin (common ending: -osin) |
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Term
| what is the effect of prazosin administration (alpha1 blocker)? |
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Definition
| TPR decrease, decreased venous return to the heart, decreased BP, decreased cardiac preload, and *no effect on the baroreflex function (hypertensive pts) |
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Term
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Definition
| an analog of prazosin which is less potent, more specific, more water soluble, has higher bioavilibility, and longer half life |
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Term
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Definition
| analog of prazosin which has a longer half life |
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Term
| what is the one alpha 2 blocker we need to know? |
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Definition
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Term
| what is the effect of yohimbine administration? what is it used for? |
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Definition
| yohimbine will increase BP, HR and antagonizes serotonin receptors. the only condition it is prescribed for is psychogenic impotence. ADRs: enhanced motor activity and tremor production |
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Term
| what are the beta blockers? |
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Definition
| non selective: propranolol, timolol, nadolol, pindolol, carteolol, penbutolol. selective: metoprolol, atenolol, acebutolol, and esmolol |
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Term
| what are the general effects of beta-blockers? |
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Definition
| decreased HR, contractility, cardiac output and BP. the relationship between the cardiac O2 supply/demand is made more balanced and efficient - supply is increased, demand is increased. |
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Term
| how do beta blockers affect the cardiac rhythm? |
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Definition
| they decrease the sinus rate, decrease the spontaneous rate of depolarization of ectopic pacemakers, decrease the conduction in the atria/AV node, and increase the effective refractory period of the AV node (antiarhythmic efficacy) |
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Term
| how do beta blockers affect renin? norepi? |
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Definition
| they attenuate the release of both |
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Term
| how do beta blockers affect respiration and metabolism? |
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Definition
| beta blockers cause bronchoconstriction (activation of beta2 = dilation) and decrease plasma concentration of glucose, lactate, and free fatty acids (also opposite of beta2 effect) |
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Term
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Definition
| the prototype beta (1+2) blocker which has membrane stabilizing effects and no intrinsic sympathomimetic activity |
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Term
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Definition
| short acting and potent, same as propanolol |
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Term
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Definition
| some as propranolol, but longer acting |
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Term
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Definition
| beta antagonist and beta partial agonist, it has intrinsic sympathomimetic activity and low membrane stabilizing activity |
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Term
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Definition
| beta antagonist with some intrinsic sympathomimetic activity |
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Term
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Definition
| beta antagonist with some intrinsic sympathomimetic activity |
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Term
| what is the benefit of selective beta1 blockers? |
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Definition
| these block most of the actions of epi and norepi on the heart, with little or no effect on the beta2 (bronchial) or alpha (vasoconstriction) |
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Term
| what are the selective beta1 blockers? |
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Definition
| metoprolol, atenolol, acebutolol, and esmolol |
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Term
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Definition
| a beta1 blocker with no intrinsic sympathomimetic activity/low membrane stabilizing activity |
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Term
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Definition
| a beta1 blocker with a longer half life than metoprolol and no intrinsic sympathomimetic activity and no membrane stabilizing activity |
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Term
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Definition
| a beta1 blocker with some intrinsive sympathomimetic activity and some low membrane stabilizing activity |
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Term
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Definition
| a beta1 blocker with a very short half life and no intrinsic sympathomimetic activity/low membrane stabilizing activity |
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Term
| what are ADRs associated with the beta blockers? |
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Definition
| congestive heart failure, bradyarrythmia (partial or complete AV conduction deficits), and bronchoconstriction (only if there is also beta2 blocking or asthma involved), fatigue, nightmares, depression, hypoglycemia (*which may not get recognized), which can cause delayed recovery from insulin, CNS: fatigue, insomnia, nightmares, and depression. **all of these usually due to total beta blockade (OD) |
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Term
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Definition
| this drug will block alpha1, beta1+2 receptors (higher beta block potency) and is a partial agonist for beta2. it inhibits neuronal uptake of NE. |
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Term
| what are the effects of labetalol? |
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Definition
| alpha1 blockage: relaxation of arterial smooth muscle, vasodilation. beta1 blockage: block reflex sympathetic stimulation of the heart. beta2 blockage: intrinsic sympathomimetic activity which *may contribute to vasodilation |
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