Endogenous/Drug effects on receptor Flashcards

Question

Place in order affinity for A1&A2 Isoprotenrol epi norepi

Answer 1

epi norepi isoproterenol epi>=NE>>i

Answer 2

``` B1 Isoprotenrol epi norepi i>epi=NE ```

Answer 3

Isoprotenrol epi norepi i>=epi>>NE

Answer 4

Short term cardiac decompensation states(post CT surg, acute MI, CHF

Answer 5

down regulation of b adrenergic receptors would decrease its effectiveness.

Answer 6

ventricular ectopy.

Answer 7

norepi adrenal medulla 97%

Answer 8

B3 lipolysis

Answer 9

Potassium | Increased Na-K pump action

Answer 10

HTN crisis | moa inhibitors

Answer 11

release of free fatty acids and in | energy production

Answer 12

force of contraction

Answer 13

conduction speed

Answer 14

bronchodilator selective B2 agonist resistant to methylation by COMT

Answer 15

``` Terbutaline is a bronchodilator selective B2 agonist can be give subq 0.25mg can repeat Q15 rapid onset ```

Answer 16

bronchodilator selective B2 agonist works in 15 min

Answer 17

bronchodilator selective B2 agonist R-enantiomer= less SE

Answer 18

Tocolytic | selective B2 agonist

Answer 19

hydroxyl group at pos 4

Answer 20

clonidine or dexmedetomidine

Answer 21

D1 receptor agonist | vasodilator for acute treatment of severe HTN

Answer 22

Acts indirectly by releasing biogenic amines from storage sites in nerve terminals – Activates RAS – Can cause psychosis (5-HT mediated) – Anorectic, locomotor stimulant (DA mediated

Answer 23

-Phenoxybenzamine-vasodilator -Blocks A1 & A2 irreversibly/Antagonists -Causes decrease in SVR and increase in CO (reflex) – Hypotension enhanced with b2 agonists – Useful in pheochromocytoma and in -autonomic hyperreflexia, SC injury

Answer 24

``` Phentolamine Blocks A1 &A2 receptors COMPETITIVELY – Mainly used in preoperative management of pheochromocytoma • Same as phenoxybenzamine, but short-lived (~15 min following IV bolus) – Causes release of histamine • Contraindicated in CAD ```

Answer 25

Prazosin/CHF Potent A1 receptor antagonist/no A2 blockade (no increase in NE release) • Blocks A1 receptors in arterioles • Decreases SVR & venous return to heart – Does not usually cause increase in HR or SV • half-life 2-3 hours • Terazosin (Hytrin®) is structural analog of prazosin – Also has high specificity for A1 receptors

Answer 26

A1-Adrenergic Antagonists Therapeutic uses -CHF/A1 receptor blockade dilates arteries • Decrease afterload and preload -BPH • A1 receptor antagonists reduce resistance in some patients • A1 receptors in bladder trigone and urethra contribute to blockage • Essential hypertension & prostatic hypertrophy (prazosin, doxazosin, terazosin)

Answer 27

``` Erectile dysfunction (Yohimbine) • Blockade with selective antagonists (yohimbine) can increase sympathetic outflow A2 receptor antagonist • Increase SNS activity • Inhibits the function of monoamine oxidase enzymes ```

Answer 28

* Hypertension * Pheochromocytoma * Benign prostatic hyperplasia * Peripheral vascular disease * Erectile dysfunction (Yohimbine)

Answer 29

Used to Tx: CAD, HTN, HF, tachydysrhythmias

Answer 30

Atenolol, metoprolol, esmolol -Relative selectivity; much less vascular, bronchial smooth muscle, and metabolic effects

Answer 31

Pindolol, acebutolol Less slowing of HR at rest; exercise induced ↑ HR still blunted like non-ISA β-blockers

Answer 32

Acebutolol, labetalol, metoprolol, pindolol, and | propranolol

Answer 33

Nebivolol vasodilates via endothelial dependent | NO pathway

Answer 34

renin release caused by SNS stimulation Reduction in plasma renin activity causes anti-HTN

Answer 35

decreased sinus rate, spontaneous & | depolarization of ectopic foci

Answer 36

COPD & asthma | blocks B2 receptor

Answer 37

Beta blockers cause hypoglycemia. Why ? Metabolic effects – Catecholamines promote glycogenolysis and mobilize glucose in response to hypoglycemia -B adrenergic antagonists may block this response -B2 receptor blockade may inhibit hepatic response to insulin-induced hypoglycemia -B3 adrenergic antagonists attenuate the release of free fatty acids from adipose tissue

Answer 38

non selective beta Interacts with B1& B2 receptors with equal affinity Highly lipophilic with large VD • Crosses BBB – Lacks intrinsic sympathomimetic activity – Extensively metabolized – Propranolol may be administered IV for management of life-threatening dysrhythmias or to patients under anesthesia • 1-3 mg administered slowly • If bradycardia is profound - atropine may be used

Answer 39

``` Metoprolol – β1/β2-receptor affinity (30:1); membrane stabilizing activity (MSA); no ISA – Primarily liver metabolism – ½ as potent as propranolol – Short elimination half-life 3.5 hrs ```

Answer 40

β1/β2-receptor affinity (30:1); no MSA or ISA activity – Primarily excreted via kidneys; no first-pass metabolism – Elimination half-life 6.5 hrs, so once daily dosing

Answer 41

Nonselective β–blocker that has MSA and | ISA

Answer 42

β1-selective with ISA

Answer 43

β1-selective; IV rapid onset and offset (<10 min.) – Rapid hydrolysis by non-specific esterases

Answer 44

Esmolol • B1 selective adrenergic antagonist with very short duration of action t1/2B 8-9 minutes • Esmolol has an ester linkage (nonspecific esterases – red blood cells) • Rapidly hydrolyzed • Onset (2 minutes) and cessation of B adrenergic blockade are rapid • Peak hemodynamic effect in 10 minutes • Esmolol has little, if any, ISA • Anesthesia uses: – Rapid, brief control of ↑ HR (i.e.: to prevent tachycardia from intubation stimulation) – Infusions can be quickly terminated if needed

Answer 45

Dont hold beta blockers, control rate <80 | beta blocker time out

Answer 46

``` Competitive antagonists at A1 and B receptors – Selective a and nonselective b blocker – Racemic mixture with 4 stereoisomers a1 blockade leads to arteriolar dilation b1 blockade leads to decrease in BP by blocking reflex sympathetic stimulation • 5x-10x more potent b blocker than a blocker (7:1) • Extensively metabolized in liver • Elimination half life of 5 hrs • Onset 2-5 minutes, peak 5-15 minutes, and DOA 2-4 hrs • 5-10 mg TTE every 10 minutes ```

Answer 47

``` • Bronchoconstriction • Bradycardia, A-V block, cardiac arrest • Decreased cardiac output • Sudden withdrawal problems • Hypoglycemia problems • Diminished exercise performance • Possible changes in blood lipids • Potential CNS effects ```

Answer 48

dopamine/dobutamine

Answer 49

phenylephrine

Answer 50

propranolol

Answer 51

terazosin or prazosin

Answer 52

* Hypertension * Ischemic heart disease * Cardiac arrhythmias * Obstructive cardiomyopathy * Congestive heart failure * Open-angle glaucoma B1 * Migraine headache * Muscle tremor, performance anxiety propranolol

Answer 53

echothiopate

Answer 54

edrophonium, neostigmine, physostigmine

Answer 55

M3 muscarinic agonist Used post-op to treat urinary retention and abdominal distention – Treat neurogenic G.I. atony and megacolon (increase intestinal motility)

Answer 56

m3 muscarinic Pilocarpine - topical miotic, glaucoma (decrease intraocular pressure

Answer 57

``` Reduces IOP by causing contraction of ciliary body • facilitates aqueous humor outflow • can be treated with cholinergic agonists or cholinesterase inhibitors ```

Answer 58

CNS effects occur with high doses of atropine – effects from restlessness to somnolence – toxic doses cause more prominent symptoms • disorientation, hallucinations, and delirium – larger (toxic) doses cause depression, circulatory collapse

Answer 59

``` less likely to change heart depresses RAS – may cause delayed awakening from anesthesia – used for motion-sickness • blocks medullary impulses arising from vestibular overstimulation • transdermal (postauricular) provides sustained blood levels Scopolamine in therapeutic doses may be used for sedation – can be combined with an opioid – drowsiness, amnesia, and fatigue – Intravenous dosing (0.3-0.6 mg ```

Answer 60

Glycopyrrolate is a quaternary amine – devoid of sedative effects – does not cross BBB

Answer 61

in narrowangle glaucoma • causes flow obstruction • interferes with flow of aqueous humor

Answer 62

``` Scopolamine produces sedation by decreasing activity of the RAS (100x more than atropine) – Also effects other areas of brain resulting in amnesia • May have delayed awakening • Physostigmine is effective in reversing restlessness or somnolence from CNS effects of tertiary amine antimuscarinics ```

Answer 63

``` Scopolamine produces sedation by decreasing activity of the RAS (100x more than atropine) – Also effects other areas of brain resulting in amnesia • May have delayed awakening • Physostigmine is effective in reversing restlessness or somnolence from CNS effects of tertiary amine antimuscarinics ```

Answer 64

scopolamine glycopyrrolate atropine

Answer 65

``` Stellate ganglion – Superior, middle, and cervicothoracic ganglia – Spinal segments T1-4/5 synapse here – Provide SNS innervation of ↑ ext., head, neck – So? – Horner syndrome • Ptosis • Miosis • Anhidrosis • Enophthalmos • Redness of face and conjunctiva ```

Answer 66

Precursor of NE • Effects are mediated through D1 receptors • Low doses primarily activate D1 receptors – Vascular postjunctional D1 receptors in renal and mesenteric blood vessels – 0.5-3.0 mcg/kg/min • Moderate DA dosages act on B1 receptors – 3.0 - 10 mcg/kg/min Higher dosages 10 - 20 mcg/kg/min primarily act at a1 receptors – Leads to vascular vasoconstriction – Low dose increased renal blood flow and GFR – Moderate dose increases myocardial contractility and increase in CO – High dosages vasoconstriction • Benefit to renal perfusion may be lost – Dopamine is an important central neurotransmitter • Peripherally administered dopamine has no central side effects • Substrate for MAO & COMT – Half-life of about a minute

Answer 67

quaternary compounds used to treat reactive airway disease – used as an inhalant – does not impair mucociliary elevator – toxicity not usually a problem since this compound is poorly absorbed from lungs into circulation

Answer 68

irreversible indirect | glaucoma

Answer 69

labetalol, chf