Autonomic Drugs Flashcards

1
Q

Mydriasis can be caused by contraction of the radial fibers of the iris, these smooth muscle cells have _______ receptors

A

Alpha receptors

  • Phenylephrine (selective adrenoceptors)
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2
Q

Minoxidil is a powerful arteriolar vasodilator that does not act on autonomic receptors. What are the following effects?

A

Tachycardia and increased cardiac contractility

  • Because of the compensatory responses, a drug that directly decreases blood pressure through a decrease in peripheral vascular resistance will cause a reflex increase in sympathetic outflow
    • Heart rate and cardiac force will increase
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3
Q

Full activation of the parasympathetic nerves is likely to produce ____________

A
  • pupillary constrictor muscle (Miosis)
  • bronchial and intestinal muscle contration
  • bradycardia
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4
Q

Norepinephrine acts at presynaptic _________adrenoreceptors and postsynaptic ___________ adrenporecptors

A

Alpha 2

Alpha 1

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5
Q

ganglion blockade results in ______ blood pressure, bowel activity and sweating

A

Decreased

  • Because the parasympathetic system dominates the pupil and SA node, it will cause mydriasis and tachycardia
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6
Q

The nerves innervating the pupillary constrictor muscle are __________________ cholinergic nerve

A

postganglionic parasympathetic

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7
Q

Pupillary muscle dilator contains__________

A

Alpha 1 adrenoceptors

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8
Q

Botulinum toxin impairs all types of ____________ transmission

A

Cholinergic

  • including transmission at ganglionic synapses and somatic motor nerve endings
  • prevents discharge of vesicular transmitter content from cholinergic nerve endings
  • cyclop;egia
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9
Q

primary neurotransmitter agent normally released in the sinoatrial node of the heart in response to a blood pressure_________-

A

Acetylcholine

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10
Q

The _________ transports norepinephrine back into the nerve ending after release and is blocked by cocaine

A

Reuptake carrier

  • Amphetamine is a substrate of NET but does not block it
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11
Q

______ and ______ block transporters in cholinergic nerves

A

Hemicholinium abd vesamicol

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12
Q

sympathomimetic drug that facilitates the release of catecholamines from adrenergic nerve endings

A

Amphetamine

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13
Q

Bacterial toxin that enzymatically disables release of acetylcholine from cholinergic nerve endings

A

Botulinum toxin

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14
Q

Important central nervous system transmitter with some peripheral effects (renal vasodilation, cardiac stimulation)

A

Dopamine

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15
Q

Research drug the inhibits transport choline into cholinergic nerve endings

A

Hemicholiniums

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16
Q

research drug that blocks all ANS ganglia and prevents autonomic compensatory reflexes

A

Hexamethonium

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17
Q

Inhibitor of tyrosine hydroxylase, the rate limiting enzyme in NE synthesis

A

Metyrosine

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18
Q

Primary transmitter at most sympathetic postganglionic nerve endings; important CNS transmitter

A

Norepinephrine

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19
Q

Drugs that inhibits VMAT, transported odf dopamine and norepinephrine into transmitter vesicles of adrenergic nerves

A

Reserpine

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20
Q

Toxins that block sodium channel and therby limit transmission in all nerve fibers

A

tetrodoxin, saxitoxin

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21
Q

Drug that inhibits VAT, transported of acetylcholine into its transmitter vescles

A

Vesamicol

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22
Q

Neostigmine and bethanechol in moderate dosage have different effects on the ____________

A

Vascular endothelium

  • Neostigmine
    • acts on the enzyme cholinesterase which is present at all cholinergic synapses
    • increases acetylcholine effects at nicotinic junctions
  • Bethanechol
    • direct acting agent that activates muscarinic receptors regardless of wheter the receptors are innervated or not
  • The muscarinic receptors on vascular endothelial cells are not innervated and responds only to direct-acting drugs
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23
Q

Parathion

A
  • activated by conversion to -oxon derivatives
  • lessstable than halogenated hydrocarbon insecticides of the DDT
    • less permanent in the environment
  • More toxic than malathion
  • very lipid soluble
  • rapidly absorbed through the lungs and skin
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24
Q

Best drug for distinguishing between myasthenia crisis (Insufficient therapy) and cholinergic crisis

A

Edrophonium

  • indirect acting
  • Cholinergic crisis would be worsened by a cholinomimetic, we choose the shortest-acting cholinesterase inhibitor
25
Q

most important cause of acute deaths in organophosphate poisoning

A

respiratory failure from neuromuscular paralysis or CNS deptession

26
Q

Cholinesterase inhibition is typically associated with ___________

A

bowel activity (diarrhea)

  • Pyridostigmine
  • neostigmine
    • prototypic carbamate
    • AChE inhibitors
27
Q

Parasympathetic nerve stimulation and a slow infusion of bethanechol will each __________

A

Increase bronchial smooth muscle tone

28
Q

direct acting cholinomimetic that is lipid soluble and is used to facilitate smoking cessation

A

Verenicline

29
Q

Muscarinic cholinoceptor agonists

A
  • accomondation and cyclospasm
  • for acute closure glaucoma
    • increased outflow of aqueous and decreased intraocular pressure
  • bronchospasm
  • no effect on neuromuscular transmission
  • sweating
30
Q

Cholinomimetic with little or no vascular effect, little or no CNS effect and a duration of action of about 2-4 h

A

Neostigmine

  • indirect acting (no vascular effect changes)
  • quaternary (charged) substance with poor lipid solubility and little or no CNS
31
Q

primary second-messenger process in the contraction of the ciliary muscle when focusing in near objects

A

IP3 (inosital 1,4,5 triphosphate)

  • CHolinomimetics cause smooth muscle contraction
  • through an action on M3, Gq-coupled receptors resulting in the release of intracellular calcium
32
Q

Direct acting muscarinic agonists

A
  • Bethanechol
    • Bladder and bowel atony, for example, after surgery or spinal cord injury
    • poor lipid solubility
  • Pilocarpine
    • sjoren’s syndrome (increases salivation). Was used in glaucoma (causes miosis, cyclospasm)
    • good lipid solubility
  • Muscarine
    • alkaloid found in mushrooms
    • low lipid solubility but readily absorbed from gut
33
Q

Direct acting nicotinic agonists

A
  • Nicotine
    • Activates all nicotinic receptors, opens Na-K channels in ganglia and neuromuscular end plates
  • Varenicline
    • partial agonists at N receptors
    • smoking cessation
  • Succinylcholine
    • N-receptor agonist, moderately selective for neuromuscular end plate
    • initial muscle spasm and postopertaive pain
    • prolonged action in persons abnormal butyrylcholinesterase
34
Q

Indirect acting alcohol

A
  • Edrophonium
    • inhibitor cholinesterase
    • amplifier of endogenously released ACh
    • Reversal of Nm block nondepolarizing drugs
35
Q

Indirect acting cabimates

A
  • Neostigmine
    • like edrophonium plus small direct nicotinic agonist action
    • Reversal of Nm block
  • Pyridostigmine
    • like edrophoniu,
    • treatment for myasthenia
  • Physostigmine
    • like edrophonium
    • Reversal of severe atropine posioning (IV). Occasionally used in acute glaucoma (topical)
36
Q

Atropine causes __________ (HR)

A

Tachycardia (Overdose)

Bradycardia (small doses)

37
Q

Most dangerous effect if beladonna alkalids in infants and toddlers

A

Hyperthermia

38
Q

Atropine blocks _______ receptors and inhibits ________ effects

A

Muscarinic

parasympathomimetic

39
Q

______ can induce both parasympathomimetic and sympathomimetic reffects by virtue of it ganglion stimualting actions

A

Nicotine

40
Q

Distinguish between an overdose of a ganglion blocker versus a muscarinic blocker?

A

Postural hypotension

41
Q

decreased DAG in salivary gland tissue is an effect of

A

antimuscarinic drug

42
Q

_______causes vasodialtion by directly activating muscarinic receptors on the endothelium of blood vessels. this effect can be blocked by atropine

A

Bethanechol

43
Q

_____has very high affinity for the phosphorous atom in organophosphate insecticides

A

Pralidoxime

44
Q

Antimuscarinic, nonselective

A

Atropine

  • Competitive pharmacologic antagonist at all M receptors
  • Mydriatic, cycloplegic
  • antidote for cholinesterase inhibitor toxicity
  • lipid soluble
45
Q

Pirenzepine, telenzepine

A

Significant M1 selectivity

46
Q

Antinicotinic ganglion blockers

A

Hexamethonium

selective Nn of receptors

47
Q

Pupillary dialtion but not cycloplegia

A

Phenyelphrine

  • antimuscarinics are mydriatic and cycloplegic
  • alpha-sympathomimetic agonists are Mydriatic only
48
Q

dual blood pressure effects

A

Clonidine

  • direct alpha agonist, vasoconstrictor effect
    • but when given for a wekk, it is accumulated in a blood pressure controllingc center
49
Q

_____cause decrease in diastolic BP and little change in systolic BP. LArge increase in pulse pressure

A

Isoproterenol

  • The decrease in diastolic blood pressure sugests that the drug decreased vascular resistance, that is it must have significant muscarinic or B agonsit effects
50
Q

Epinephrine

A

a1, a2, B1, B2, B3 agonist

51
Q

Norepinephrine

A

a1, a1, B1, B3

52
Q

isoproternol

A

B1, B2, B3 agonist

used as nebulizer and IV (in AV block)

53
Q

Dobutamine

A

B1 agonist’

Primarily used in acute failure to increase cardiac output

54
Q

Effects of epinephrine would be blocked by prasozin but not metoprolol

A

Mydriasis

55
Q

Nonselective alpha blocker

A

Phentolamine

Phenoxybenzamine

56
Q

Alpha 1 selective alpha blocker

A

Prasozin

57
Q

Alpha 2 blockers

A

Yohimbine

58
Q
A