Exam 2 Drugs

Question 1

sypmathomimetic subclasses:

Answer 1

direct acting
indirect acting

Question 2

midodrine

Answer 2

class: direct-acting (DA) sympathomimetic

receptor: alpha-1 agonist

indication: orthostatic hypotension

Question 3

clonidine

Answer 3

class: DA sympathomimetic
receptor: CENTRAL alpha-2 agonist; considered a PARTIAL AGONIST
indication:
* HTN (off label: adjuvant drug for sedation)
* diarrhea
* hot flashes
* hemodynamic instability intraOP
* ADHD, Tourettes, withdrawal symptoms
* OFF LABEL: anxiety, PTSD, adjunct to anesthesia (prolongs anesthesia)

MOA:
CENTRAL Alpha-2 receptors are located in the rostro-ventral lateral medulla (RVLM)
*alpha-2 is stimulated
* INCREASED firing of CN X (vagal) > INCREASED release of ACh onto SA node > decreased HR
* DECREAESD firing of sympathetic nerves in the chain ganglion > INCREASED venodilation of veins and arteries > decreased stroke volume
* overall effects of decrased HR and decreased SV will decrease BP

SE:
* dry mouth
* also has effect to induce sedation

Question 4

epinephrine

Answer 4

class: DA sympathomimetic
receptor: alpha + beta 1 + beta 2 agonist
indication: positive inotropic agent, positive chronotropic agent, dilation of skeletal muscles and bronchioles

Question 5

norepi (NE)

Answer 5

class: DA sympathomimetic
receptor: alpha + beta 1 agonist
indication: hypotension
MOA: increase in SBP + DBP; vagal reflex overcomes chronotropic effects (does not stimulate HR as much)

Question 6

isoproterenol

Answer 6

class: DA sympathomimetic
receptor: beta 1 + beta 2 agonist
indication: HTN

Question 7

dopamine

Answer 7

class: DA sympathomimetic
receptor:D + beta 1 agonist
indication: cardiac
MOA:
* decreases peripheral resistance at LOW DOSES (induces diuresis)
* mimics action of epinephrine at HIGH RATES OF INFUSION (increase in HR, increase in contractility, increase in peripheral resistance, could be arrythmogenic)

Question 8

dobutamine (dobs)

Answer 8

class: DA sympathomimetic
receptor:beta 1 selective agonist
indication: cardiogenic shock, HF
MOA: positive inotropic/chronotropic effect

Question 9

phenylephrine

Answer 9

class: DA sympathomimetic
receptor: pure alpha agonist
indication: decongestant, hypotension

Question 10

midodrine

Answer 10

class: DA sympathomimetic
receptor: alpha-1 selective agonist
indication: postural/orthostatic hypotension

Question 11

ephedrine

Answer 11

class: DA && INDIRECT ACTING sympathomimetic
receptor: alpha and beta agonist
indication: nasal decongestant (pseudoephedrine)
MOA: mimics epi (direct-acting); crosses the BBB

found in plants; can be used to make meth

Question 12

dexmedetomidine

Answer 12

class: DA sympathomimetic
receptor: CENTRAL alpha-2-A selective agonist
indication: anxiolytic

MOA: induces anesthesia, analgesia, sympatholysis, sedation, anxiolysis, hypnosis, and increased congnition

Question 13

amphetamines

Answer 13

class: INDIRECT-acting sympathomimetics
effects: mood elevator, appetite suppresant, increased attention
MOA: readily enter CNS

methamphetamines have a higher ratio of CNS to PNS actions

Question 14

cocaine

Answer 14

class: indirect acting sympathomimetic
effects: amphetamine-like effects
MOA: inhibits dopamine reuptake into neurons in the “pleasure centers” of the brain

Question 15

tyramine

Answer 15

class: indirect sympathomimetic
effects: releases stored catecholamines; metabolized by MAO

MAOIs (monoamine oxidase inhibitor) inhibit the breakdown of NTs and are often prescribed as antidepressants; MAOis may increase blood pressure after eating fermented foods

ex) cheese, chicken liver, sausage (fermented), red wine, yeast

Question 16

phentolamine

Answer 16

class: reversible sympatholytic
receptor: alpha-1, alpha-2 blocker
indication: HTN, cardiac stimulant

Question 17

prazosin

Answer 17

class: reversible sympatholytic
receptor: alpha-1 selective blocker (low affinity for alpha-2)
indication: HTN, BPH
MOA: relaxes arterial and venous smooth muscle

Question 18

labetalol

Answer 18

class: reversible sympatholytic
receptor: alpha & beta blocker
indication: HTN

Question 19

phenoxybenzamine

Answer 19

class: IRREVERSIBLE sympatholytic
receptor: non-specific alpha antagonist & covalently bonds, minor agonist of muscarinic and histamine receptors
indication: HTN linked to
pheochromocytoma; can be used as a direct injection for erectile dysfunction
SE: cardiac stimulation, abdominal pain, NVD (at higher levels), priaprism
MOA: inhihbits NE reuptake

Question 20

-osin drug class

Answer 20

alpha-1 blockers

Question 21

what is the drug Yohimbine?

Answer 21

an alpha-2 selective antagonist which has little use clinically

allegedly helps ED patients

Question 22

propanolol

Answer 22

class: sympatholytic
receptor: non-specific beta blocker
indication: HTN
SE: bradycardia, rash, fever, CNS effects (sedation, sleep disturbances, depression), worsening of asthma (B2), hypoglyemia in diabetics (blocks glycogenolysis), must discontinue use gradually

Question 23

metoprolol

Answer 23

class: sympatholytic
receptor: beta-1 blocker
indication: HTN (safer in COPD, asthma, and diabetic patients)

Question 24

labetalol

Answer 24

class: sympatholytic
receptor: a1 **AND **b1, b2 blocker
indication: HTN, preeclampsia, pheochromocytoma

racemic mixture: 2 active forms and 2 inactive forms

Question 25

esmolol

Answer 25

class: sympatholytic
receptor: beta-1 selective blocker
indication: tachycardia intraop, supraventricular arrythmia
other facts: ultra short acting, steady state infusion, terminated rapidly when discontinued, safer in critical care patients

Question 26

ACh

Answer 26

class: DA parasympathomimetic
subclass: choline ester
indication: miosis (pupillary constriction)

insoluble in lipids

Question 27

methacholine

Answer 27

class: DA parasympathomimetic
subclass: choline ester
indication: diagnostic drug for asthma

insoluble in lipids

Question 28

carbachol

Answer 28

class: DA parasympathomimetic
subclass: choline ester
indication: to decrease IOP

insoluble in lipids; resistant to hydrolysis

Question 29

bethanechol

Answer 29

class: DA parasympathomimetic
subclass: choline ester
indication: bladder dysfunction, reflux disease

insoluble in lipids; resistant to hydrolysis

Question 30

muscarine

Answer 30

class: DA parasympathomimetic
subclass: alkaloid
effects: mimics parasympathetic nerve discharge (saliva, bowel motility, urination, etc.)
MOA: takes place at effector cells, not in ganglia
toxicity: exaggeration of all symptoms of muscarinic agonism (MYCETISM); can occur with high consumption of wild mushrooms
reversal for toxicity: ATROPINE 1-2mg IM

Question 31

nicotine

Answer 31

class: DA parasympathomimetic
subclass: alkaloid
MOA: stimulates autonomic ganglia and skeletal muscle NMJ, not effector cells
release of dopamine, serotonin, GABA, and NE
SE: in larger doses – tremors, emesis, stimulates respiratory center, convulsions, fatal coma (OD ingestion), addiction

crosses BBB; lipid soluble

Question 32

arecoline

Answer 32

class: DA parasympathomimetic
subclass: alkaloid
stimulant; from betel nut

Question 33

pilocarpine

Answer 33

class: DA parasympathomimetic
subclass: alkaloid
effects: N/V/D, salivation, sweating, bronchial constriction

Question 34

edrophonium

Answer 34

class: INDIRECT-acting parasympathomimetic
subclass: simple alcohol
indication: diagonist drug for myasthenia gravis
onset: 5-15 mins

Question 35

neostigmine

Answer 35

class: INDIRECT-acting parasympathomimetic
subclass: carbamate
indication: MG, surgical paralysis reversal agent
MOA: inhibits the effects of AChE

Question 36

pyridostigmine

Answer 36

class: INDIRECT-acting parasympathomimetic
subclass: carbamate
indication: MG
MOA: inhibits the effects of AChE

Question 37

echothiophate

Answer 37

class: INDIRECT-acting parasympathomimetic
subclass: organophosphate
indication: glaucoma
MOA: increases the drainage of intraocular fluid

Question 38

atropine

Answer 38

class: parasympatholytic
subclass: antimuscarinic
indication: organophosphate poisoning (with pralidoxime), bradycardia

• effects occur d/t racemix mixture
• competitively inhibits muscarinic responses to ACh

Question 39

scopolamine

Answer 39

class: parasympatholytic
subclass: antimuscarinic
indication: motion sickness, excessive salivation

Question 40

tropicamide

Answer 40

class: parasympatholytic
subclass: antimuscarinic
indication: mydriasis and cycloplegia (diagnostic drug)

Question 41

ipratropium bromide

Answer 41

class: parasympatholytic
subclass: antimuscarinic
indication: asthma

Question 42

succinylcholine

Answer 42

class: parasympatholytic
subclass: antinicotinic
indication: DEPOLARIZING muscle relaxant
MOA:
* resembles ACh; it is considered a n-ACh-R AGONIST
* blocks n-ACh-R on motor end plate of skeletal muscle
* depolarization PERSISTS
* continuous end-plate depolarization causes muscle relaxation (prolonged depol = delayed repolarization of cell)
* this depolarizing agent causes a PHASE I BLOCK (depol w/ lack of repolarization) which will then lead to a phase II block
SE:
* fasciculations
* muscle pain (when drug is bound for too long)
* hyperK+
* MH
* apnea

Question 43

curare derivatives (i.e. rocuronium)

Answer 43

class: parasympatholytic
subclass: antinicotinic
indication: NON-depolarizing NMBA
**MOA: **
* competitive with ACh at n-ACh-Rs; acts as a COMPETITIVE ANTAGONIST
* does NOT depolarize motor end plate
* excessive [ ] = channel blockade

the reversal for ND-NMBAs is SUGGAMADEX

Question 44

suggamadex

Answer 44

reversal agent for NON-DEPOLARIZING NMBAs

a cyclic molecule that cycles around the non-depolarizing blocking agent to prevent binding at the receptor site

Question 45

methyldopa

Answer 45

class: sympathoplegic
subclass: centrally acting alpha 2 agonist
indication: pregnancy induced HTN, (does NOT cross placental barrier); not first-line for normal HTN

Question 46

hydralazine

Answer 46

class: oral vasodilator
indication: HTN
MOA:
* induces NO production in endothelium to relax smooth muscle of arterioles
* reduces peripheral vascular resistance
* reduces MAP
pharmacokinetics: well abosrbed, rapid first pass metab, tachyphylaxis
SE: HA, nausea, sweating, flushing, worse in slow ACETYLATORS (phase II metabolism); symptoms resemble LUPUS

Question 47

mioxidil

Answer 47

class: oral vasodilator
indication: HTN, hair growth (rogaine)
MOA:
* opens K+ channels in smooth muscles; stabilizes potential which will decrease likelihood to fire AP
* dilates arteries and arterioles
pharmacokinetics: well absorbed, typically rogaine
SE: HA, sweating, palpitations, tachycardia, angina, hypertrichosis (hair growth)

Question 48

nitroprusside

Answer 48

class: vasodilator
indication: HT emergency, cardiac failure
MOA:
* relaxes vascular smooth muscle
* breaks down in blood to release NO
* NO > increased cGMP > vasodilation of arteries and veins
SE:
* rapidly lowers BP
* higher rates cause toxicity: CN accumulation will occur (met acidosis, arrhythmias, death – worse in renal insufficiency patients)

sodium thiosulfate facilitates metabolism of cyanide

Question 49

fenoldopam

Answer 49

class: vasodilator
subclass: D1 agonist
indication: HTN emergencies, post-op HTN
MOA: peripheral arteriolar dilator; increases renal blood flow to promote diuresis

Question 50

calcium channel blockers

Answer 50

class: CCBs - vasodilators
indication: HTN, anti-anginal, anti-arrhythmic
MOA: blocks mostly L-type Ca2+ channels in the heart and inhibits Ca2+ influx in arterial smooth muscle

ex) verapamil, diltiazem, dihydropyridines (-dipines, i.e. nicardipine)

Question 51

ace inhibitors

Answer 51

class: anti-angiotensins
indication: HTN
MOA: inhibits the synthesis of angiotensin I to convert to angiotensin II by blocking the ACE enzyme
* decreaes PVR
* CO & HR are not significantly changed
* eliminated via kidneys
SE:
* severe hypotension
* teratogenic: contraindicated in pregnant women and especially those in their first trimester
* altereed sense of taste
* rashes
drug interactions:
* K+ supplements can lead to hyperK+
* NSAIDS block some effects
* DRY COUGH (d/t bradykinin build up; ACE converts bradykinin to its inactive metabolites, so inhibiting ACE would cause a build up of bradykinin

ex) -prils (i.e. captopril, lisinopril, enalapril)

Question 52

ARBs

Answer 52

class: anti-angiotensin
indication: HTN
MOA:
* ARBs block ATII from binding to receptor sites at sites where vasoconstriction would occur, as well as on the adrenal cortex where aldosterone gets secreted; by blocking vasoconstriction as well as aldosterone secretion, the overall effect is decreased PVR and decreased sodium/water retention, lowering overall BP

ex) -sartans (i.e. losartan, valsartan)

no effect on bradykinin, since ACE is not being inhibited, therefore NO cough symptoms associated

Question 53

bosentan (tracleer)

Answer 53

class: endothelin receptor antagonist
indication: PAHTN
MOA:
* blocks ET-1 from binding to ETa and ETb
* ET-1 is the active form of an endogenous product created in the lungs; normally ET-1 when bound to ETa receptors will cause vasoconstriction and increased cell proliferation
* when ET-1 is blocked from binding to ETa-Rs, there will be an increase in vasodilation in the pulmonary circulation as well as decreased cell proliferation to help with vascular remodeling
SE: HA, edema, rash, hepatotoxicity, teratogenic

Question 54

nitroglycerin

Answer 54

class: vasodilator
indication: angina, HTN
MOA:
* NO release in vascular smooth muscle
* increases guanylyl cyclase
* increases cGMP
* cGMP will dephosphorylate myosin-LC-PO4 and will be left with myosin-LC
* this will cause relaxation in the vascular smooth muscle
SE: orthostatic hypotension, syncope, HA, reflex tachycardia, hemoglobin interactions (NO2- reacts with Hgb to form methemoglobin > can cause pseudocyanosis at extremely high levels, but will ALSO have a high affinity for CN in the case of CN poisoning)

mononitrate form: isosorbide dinitrate

Question 55

digoxin

Answer 55

class: cardiac glycoside
indication: positive inotropic agent
MOA:
* blocks Na+/K+/ATPase pump
* leads to increased ICF [Na+] > lowers AP duration
* slows the NCX > increases ICF [Ca2+]
* increases more forcible contractility
SE:
* has a very low therapeutic index
* pro-arrythmogenic
* increases PR int & decreases QT int
* toxic doses = tachycardia, fibrillation, cardiac arrest
* hyperK+, hyperCa2+, and hypomg2+ can occur

Question 56

milrinone

Answer 56

class: PDE3 inhibitor
indication: HF
MOA:
* PDE3 is an enzyme that inactivates cAMP/cGMP
* when PDE3 is inhibited, increases cAMP/cGMP
* more cAMP = more foricble contraction (positive inotropic effect)
* more cGMP = more vasodilation
* also increases/prolongs Ca2+ effects

Question 57

levosimendan

Answer 57

class: calcium sensitizer
indication: positive inotropic agent; vasodilation
MOA:
* binds troponin
* stabilizes Ca2+ bound conformation
* opens K+ channels (vasodilation)
* not approved in US yet