Pharmacology - chapter 7 - Adrenergic antagonists Flashcards
(45 cards)
phenoxybenzamine therapeutic uses?
pheochromocytoma, raynauds disease, frostbite, acrocyanosis.
Phenoxybezamine?
Irreversible & noncompetitive inhibitor of alpha-1 and alpha-2 receptors.
Phentolamine?
competitive block of alpha-1 & alpha-2 receptors used to treat hypertensive crisis.
Prazosin, Terazosin, Doxazosin, Tamsulosin and Alfuzosin ?
Selcetive competitive blockers of the lpha-1 receptor.
Tamsulosin & alfuzosin therapeutic uses?
Benign Prostatic hyperplasia
Prazosin, Terazosin and Doxazosin therapeutical use?
used to treat hypertension. By inhibiting alpha-receptors these drugs inhibit vasoconstriction = vasodilates. They also bind alpha receptors in adipose tissue and in liver, improving lipidprofiles and glucose metabolism in hypertensive patients.
What is “first-dose” effect?
E.g. Prazosin, terazosin and doxazosin may produce a orthostatic hypotensive response when the first dose is administered.
How to avoid “first-dose” response?
lower the first dose to 1/3rd or 1/4th of normal dose, and give drug at bedtime.
5alpha-reductase?
convert testosterone to dihydrotestosterone
Finasteride and dutasteride?
5 alpha-reductase inhibitors used to treat benign prostatic hyperplasia
A humongously horribly disastrous sideeffect of Finasteride and duasteride?
sexual dysfunction
Yohimbine?
Found as a component of the bark of the yohimbe tree. It’s a selective competitive alpha2-blocker. Works at the level of the CNS to increase sympathetic outflow.
All clinically available beta blockers are… ?
competitive antagonists
with exception of labetalol and carvediol, the name of all beta blosker end in …..?
“-olol”
Propranolol?
Beta-1 and beta-2 blocker
Effects of propanolol? 1 cardiovascular 2 respiratory 3 kidney 4 glucose
1 cardiovascular - lowers CO with negative iono-and chronotrophic effects. Prevents beta-2 mediated vasodilation = vasoconstriction.
2 respiratory - bronchoconstriction
3 decreased renal perfusion increses Na-retention.
4 glucose - beta-blockade leads to decreased glycogenolysis and glucagon secretion.
Conditions where you never treat with propranolol?
Asthma or COPD patients.
beta blockers in asthmatic diabetes patient?
use cardioselective betablockers
Drugs that inhibit or interfere with propranolol?
cimentidine, fluoxetine, paroxetine and ritonavir
drugs that stiulate or induce metabolism of propanolol?
barbiturates, phenytoin and rifampin
Timolol and nadolol?
Noselective beta antagonists that are more potent than propanolol.
Beta blockers and glaucoma?
Beta blockers are effective in treating glaucoma. The decrease the intraocular pressure by lowering the secretion of aqueous humor by the ciliary body.
Acetubulol, atenolol, metoprolol, bisoprolol, betaxolol, nebivolol og esmolol?
Beta1 selective antagonists.
beta-1 cardioselectivity and dose-relationship?
cardiospecificity is most pronounced at low doses, and lost with increased doses.