Term
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Definition
| beta-blocker with beta-1 selectivity that is a partial agonist, has membrane stabilizing effects, and has low lipid solubility |
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Term
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Definition
| beta-blocker with beta-1 selectivity that does not have any partial agonist or membrane stabilizing action; has low lipid solubility |
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Term
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Definition
| beta-blocker with beta-1 selectivity that is not a partial agonist or membrane stablizer but has low lipid solubility; shortest duration of action (10 min) due to rapid inactivation by plasma & blood cell esterases |
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Term
| metoprolol (Lopressor, Toprol-XL) |
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Definition
| beta-blocker with beta-1 selectivity that has no partial agonist activity, might have membrane stabilizing activity and has medium lipid solubility |
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Term
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Definition
| beta-blocker with beta-1 & beta-2 selectivity that has no partial agonist or membrane stabilizing activity; has lowest lipid solubility; long duration of action (24 hrs); used for more chronic conditions |
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Term
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Definition
| beta-blocerk with beta-1 & beta-2 selectivity that HAS partial agonist or membrane stabilizing effect; has medium lipid solubility |
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Term
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Definition
| beta-blocker with beta-1 & beta-2 selectivity that has no partial agonist but has some membrane stabilizing effect; has HIGH lipid solubility |
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Term
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Definition
| beta-blocker with beta-1 & beta-2 selectivity that has no partial agonist or membrane stabilizing activity; has medium lipid solubility |
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Term
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Definition
| combination beta-blocker & alpha-blocker; used to treat moderate-severe hypertension (PO) & for emergency treatment (IV) of hypertensive crisis; alpha-blocking action creates significant decrease in arterial BP due to decrease in peripheral arterial resistance, also somewhat from decrease in cardiac output (beta-1 & -2) & renin (beta-1) |
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Term
| Intrinsic Sympathetic and/or Sympathomimetic ACtivity (ISA) |
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Definition
| actions of beta-blockers that also have partial agonist activities; net effect is a preservation of at least a small amount of beta-receptor function |
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Term
| Stabilizing cell membranes |
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Definition
| property of some beta-blockers that perform "a local anesthetic" action; usually only seen at high concentrations and are more indicative of a side effect due to overdosing rather than seen at therapeutic levels |
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Term
| High Lipid Solubility of certain Beta-blockers |
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Definition
| property of beta-blockers; as this property increases, the more likely the drug will enter the brain & be cleared by the liver |
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Term
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Definition
| drug exception to the rule of lipid solubility; it has a low lipid solubility but is very rapidly inactivated in the blood by circulating esterases & has a very short duration of action |
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Term
| Inhibition of Beta-1 Receptors in Heart |
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Definition
| effects of all beta-blockers: decrease heart rate, contractility, automaticity, and conduction velocity |
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Term
| Therapeutic Use of Beta-Blockers that block beta-1 receptors (all) |
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Definition
| decreases heart rate & contractility which decreases myocardial O2 deficit which is the cause of angina in patients with poor coronary O2 delivery |
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Term
| Therapuetic Use for Beta-Blockers blocking beta-1 receptors (all) |
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Definition
| decrease in automaticity helps prevent post-MI arrhythmias; by slowing conduction velocity in A-V node, they also prevent abnormal supraventricular tachycardias & arrhythmias |
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Term
| Therapeutic Use for Beta-blockers by inhibition of beta-1 receptors (all) |
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Definition
| by inhibiting all cardiac beta-1 receptors, helps protect heart from dangerous catecholamine-induced tachycardias & arrhythmias during surgical removal of pheochromocytoma (tumore of adrenal medulla) and "thyroid storms" in hyperthyroidism |
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Term
| Ophthalmic Uses for Beta-Blockers particularly Beta-2 inhibition |
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Definition
| inhibits beta-2 receptor-mediated ciliary epithelium production of aqueous humor; used to treat glaucoma by reducing intraocular pressure; drug of choice is timolol (Timoptic) |
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Term
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Definition
| beta-1 & beta-2 receptor antagonist that is used as an ophthalmic agent to treat glaucoma by inhibiting beta-2-mediated formation of aqueous humor in the ciliary epithelium, thereby decreasing intraocular pressure due to decreased aqueous humor production |
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Term
| acebutolol (Sectral) & pindolol (Visken) |
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Definition
| two drugs, a beta-1 selective inhibitor and non-selective inhibitors, both exhibit partial agonist activity (ISA = intrinsic sympathomimetic activity); net inhibitory effects not as intense as beta-blockers without ISA; don't interfere with beta-2-mediated relaxation of blood vessels in skeletal muscle, decreasing total peripheral arterial resistance, leading to their overall anithypertensive effects |
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Term
| drugs with high lipid solubility |
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Definition
| propanolol (Inderal) - more likely to enter brain & activates CNS-related antihypertensive mechansisms; more likely to be inactivated by liver - must have good liver function |
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Term
| drugs with moderate lipid solubility |
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Definition
| metoprolol (Lopressor, Toprol-XL), pindolol (Visken), timolol (Timoptic); more likely to enter CNS and be inactivated by liver - must have good liver function |
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Term
| drugs with low lipid solubility |
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Definition
| acebutalol (Sectral), atenolol (Tenormin), esmolol (Brevibloc), nadolol (Corgard); unable to cross BBB easily to get in CNS; less inactivated by liver; more inactivated by renal excretion - must have good renal function |
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Term
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Definition
| property that may contributes to antiarrhythmic action of propanolol (Inderal) - generally need very high concentrations of drug to get this effect |
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Term
| Side Effects of Inhibition of Beta-1 Receptors |
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Definition
| excessive depression of myocardial beta-1 receptor functions leads to bradycardia, A-V blockade, excessively depressed cardiac output (aggravates Raynauds, intermittent claudication & causes exercise intolerance); masks warning sign of severe hypoglycemic reaction to insulin (marked tachycardia); rebound hypertension and/or angina with sudden withdrawal of drug |
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Term
| Side Effects Related to Inhibition of Beta-2 Receptors |
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Definition
| bronchoconstriction in asthmatics due to inhibition of beta-2-mediated bronchorelaxation; more intermittent claudication & exercise intolerance; delayed recovery from insulin-induced hypoglycemic episodes due to decreased beta-2-mediated hepatic glucose output |
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Term
| Side Effects related to Partial Agonist Activity (ISA) |
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Definition
| less severe side effects of beta-1 & beta-2 blockers: bradycardia, AV blockade, depressed cardiac output; aggravation of Raynauds, intermittent claudication, exericise intolerance; masking of severe hypoglycemic reaction to insulin via marked tachycardia; rebound hypertension &/or angina; bronchoconstriction in asthmatics; delayed recovery from insulin-induced hypoglycemic events |
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Term
| Side Effects related to Membrane Stabilization |
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Definition
| high concentrations of drug would exert highly undesirable local anesthetic effects in eyes |
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Term
| Side Effects due to Lipid Solubility |
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Definition
| incresed lipid solubility means increased CNS uptake which means more CNS side effects like depression & sleeping disorders |
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Term
| Non-specific Side Effects of Beta-Blockers |
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Definition
| aggravates insulin-resistant states in HPN & type II diabetics; abnormal blood lipid profiles |
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Term
| Side Effects of labetalol (Trandate) |
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Definition
| orthostatic hypotension (due to alpha-blockade); bronchoconstriction (due to beta-blockade); much less aggravation of Raynaud's and much less tachycardia |
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