M2: Adrenoreceptor Antagonist Drugs Flashcards
Reversible agonist
Phentolamin & Prazosin
May be reversible or irreversible
Alpha receptor antagonism
Irreversible antagonist
Phenoxybenzamine
Dec peripheral vascular resistance leads to orthostatic hypotension and reflex tachycardia. Miosis. Nasal stuffiness. Dec resistance to urine outflow.
Alpha 1 receptor antagonist
Irreversible A1 antagonist. Inhibition of NE uptake. Blocks sero, acetyl & etc. Attenuation and potentiation of catecholamine induced vasoconstriction. Treatment for pheochromocytoma. Given per orem.
Phenoxybenzamine
Diagnosis for Pheochromocytoma
Measure VMA & Ultz
Metabolic product of catecholamine breakdown
VMA
Orthostatic hypo, tachy, nasal stuffiness, inhibition of ejaculation.
SE & AE of phenoxybenzamine
Competitive antagonist of A1 & A2 receptors. Dec peripheral vascular resistance. For pheochromocytoma
Phenotalamine
Highly selective for A1 receptors. Relaxation of arterial & venule smooth muscle . For BPH. Relaxation of prostate muscle. Mgt for HPN
Prazosin/Minipress
Reversible A1 antagonist. For HPN & BPH. Extensively metabolized in the liver. Not usually used for HPN.
Terazosin
Half life is 22hrs. Longer. For HPN & BPH.
Doxazosin
A1 antagonist. High bioavailability. Inhibition of contractions in prostate smooth muscles. Less effect on standing BP.
Tamsulosin
Hypersecretion of catecholamines. Hypertension, headache, palpitation & excessive sweating.
Pheochromocytoma
Mild to moderate systemic HPN. Major adverse effect is orthostatic hypotension.
Chronic HPN
Peripheral Vascular Dse: Ar blocking agents are not effective. For reynauds phenomenon
Prazosin & Phenyoxybenzamine
Urinary Obstruction
Prazisin, Doxasozine, Terazosin& tamsulosin
Beta blockers: good oral absorption. Peak plasma concentration
1-3hrs after ingestion
Extensive first pass effect among BetaB. Low bioavailability. Noncardio selective. Notorious for asthma attacks. For hyperthyroidism.
Propanolol
BetaB that Cross the BB
Propanolol & Penbutolol
Half life is 10mins
Esmolol
Longest half life of 24hrs
Nadolol
Lower BO via (-) inotropic & chronotropic effects. Increas peripheral resistance.
BetaB
BetaB: _______ in airway resistance as a result of ______.
Inc. Bronchoconstriction.
BetaB: in eye. Dec prod of ________ in px with glaucoma. Dec IOP.
Aqueous humor
BetaB: metabolism. Inhibition of
Lypolysis & Glycogenolysis
BetaB: metabolism. Inc _____
Vldl
Prototype BetaB. Low bioavailability. Use for HPN, angina, dysrhythmia & hyperthyroidism.
Propanolol
Beta1 selective. Safer in px who experience bronchoconstriction and COPD
Metoprolol
Highly selective B1 blocker. Elicit vasodilation. Good for CHF.
Nevibolol
Long duration. Spectrum similar to timolol.
Nadulol
Non selective, ocular hypotensive effects. For patients with glaucoma
Timolol
Topical opthalmic with glaucoma
Levobunolol & Betaxoxol
Less likely to produce bradycardia & plasma lipid abnormalities
Pindolol, acebutolol, carteolol
Potent A & B blocker
Labetalol
Ultra short acting B1 blocker. Short half life 10mins. Used for SVP, perioperative HPN & antianginal agent
Esmolol
Hypertension. Effective & well tolerated. Used with a diuretic & vasodilator. Administered once or twice daily.
Beta Blockers
Used for ischemic heart dse. Dec O2 demand. Improve exercise tolerance and reduce anginal episodes. Improve survival following AMI.
Timolol, propanolol & metoprolol
Reduce ventricular ectopic beats.
Bblockers
Reduce mortality in pxs with CHF
Metoprolol, Bisoprolol & Carvedilols
For local us glaucoma which reduces IOP
Timolol
Excessive catecholamine action. Inhibition of T3 & T4.
Propranolol
Used for migraine, somatic manifestations of anxiety & alcohol withdrawal.
Propranolol
