Autonomic drugs

Question 0

What are symptoms of “cholinergic syndrome”, or cholinesterase inhibitor poisoning? Tx?

Answer 0

MS: weakness, confusion, drowsiness –> coma, seizures
Pupils: miosis (small, fixed or sl reactive)
Bradycardia, paralysis, muscle fasciculations
SLUDGE: salivation/sweating, lacrimation, urination, defecation, GI hyperactivity, emesis.
Tx: atropine (muscarinic antagonist), pralidoxime (regenerates AChE)

Question 1

What are cholinomimetics? What are the two types?

Answer 1

Drugs that increase acetylcholine signaling

1) Direct cholinergic agonists
2) Anti-cholinesterases

Question 2

Name 4 cholinergic direct agonists

Answer 2

Bethanechol, carbachol, pilocarpine, methacholine

Question 3

Name 7 acetylcholinesterase inhibitors

Answer 3

Neostigmine, pyridostigmine, physostigmine, Donepezil, rivastigmine, galantamine, edrophonium

Question 4

Bethanechol

Answer 4

Cholinergic direct agonist
Activates badder and bowel smooth muscle
Resistant to AChE
Used for post-op ileus, neurogenic ileus, urinary retention

Question 5

Carbachol

Answer 5

Direct cholinergic, ACh mimic

Used for relief of intraocular pressure, glaucoma pupillary constriction

Question 6

Pilocarpine

Answer 6

Direct cholinergic agonist
Contracts ciliary muscle of eye and pupillary sphincter, resistant to AChE
Used for glaucoma, stimulator of sweat and tears

Question 7

Methacholine

Answer 7

Direct cholinergic agonist

Works in airway to constrict airways, used as asthma challenge

Question 8

Neostigmine

Answer 8

Anticholinesterase

Used for post-op and neurogenic ileus, urinary retention, myasthenia gravis, reversal of NMJ blockade

Question 9

Pyridostigmine

Answer 9

Anticholinesterase
Used as long-acting to improve strength in myasthenia gravis
Does not penetrate CNS

Question 10

Physostigmine

Answer 10

Anticholinesterase
Used for anticholinergic toxicity (eg atropine OD)
Penetrates CNS

Question 11

Donepezil, rivastigmine, galantamine

Answer 11

Anticholinesterase

Used for Alzheimer’s disease

Question 12

Edrophonium

Answer 12

Anticholinesterase

Historically used for diagnosis of myasthenia gravis

Question 13

Treatment for cholinesterase inhibitor poisoning

Answer 13

Atropine (competitive inhibitor) and pralidoxime (regenerates AChE)

Question 14

Muscarinic Antagonist Effects

Answer 14

Oppose cholinergics. Dilate eyes, decrease secretions (airways, GI), decrease GI motility, decrease bladder urgency.

Question 15

Muscarinic antagonist toxicity

Answer 15

Hot as a hare (no sweating), dry as a bone (no secretions), red as a beet (flushing), blind as a bat (cycloplegia), mad as a hatter (disorientation), bloated as a toad (constipation and urinary retention

Question 16

Atropine

Answer 16

Muscarinic antagonist

Mydriasis and cycloplegia in eye

Question 17

Homatropine

Answer 17

Muscarinic antagonist

Mydriasis and cycloplegia in eye

Question 18

Tropicamide

Answer 18

Muscarinic antagonist

Mydriasis and cycloplegia in eye

Question 19

Benztropine

Answer 19

Muscarinic antagonist

CNS, used for Parkinson

Question 20

Scopolamine

Answer 20

Muscarinic antagonist

CNS, used for motion sickness

Question 21

Ipratropium, tiotropium

Answer 21

Muscarinic antagonist

Respiratory system, used for COPD

Question 22

Oxybutynin, darifenacin, solifenacin

Answer 22

Muscarinic antagonist

Reduces urinary urge in cystitis

Question 23

Glycopyrrolate

Answer 23

Muscarinic antagonist

GI and respiratory

Question 24

Drugs for urinary urge/incontinence

Answer 24

Oxybutynin, darifenacin, solifenacin

Question 25

Other meds with anticholinergic side effects

Answer 25

H1 antihistamines (1st gen), neuroleptics, TCAs, Jimson weed

Question 26

Anticholinergics contraindicated in

Answer 26

BPH, hyperthermia, acute angle glaucoma, GI obstruction, elderly

Question 27

Epinephrine

Answer 27

Sympathomimetic, b > a (a predominates at high doses) Used for anaphylaxis, open angle glaucoma, asthma, hypotension

Question 28

Norepinephrine

Answer 28

Sympathomimetic, a1 > a2 > b1 (HR actually decreases by reflex) Used for hypotension, except it decreases renal perfusion

Question 29

Isoproterenol

Answer 29

Beta agonist, b1 = b2 | Decreases mean arterial pressure, increases HR

Question 30

Dopamine

Answer 30

Sympathomimetic, D > b > a (can adjust dosage for effects)

Question 31

Dobutamine

Answer 31

Sympathomimetic, b1 > b2, a

Question 32

Phenylephrine

Answer 32

Sympathomimetic, a1 > a2 Used for hypotension

Question 33

Albuterol, salmeterol, terbutaline

Answer 33

Sympathomimetic, b2 > b1 Can be used for asthma and to reduce premature uterine contractions

Question 34

Amphetamine

Answer 34

Indirect sympathomimetic, general agonist and reuptake inhibitor. Used for narcolepsy, obesity, ADD

Question 35

Ephedrine

Answer 35

Indirect sypathomimetic, releases stored catecholamines. Used for nasal decongestion, urinary incontinence, hypotension

Question 36

Cocaine

Answer 36

Indirect sympathomimetic general agonist, reuptake inhibitor. Causes vasoconstriction and local anesthesia.

Question 37

Beta blockers plus cocaine?

Answer 37

Bad idea! Can lead to unopposed alpha activation, massive hypertension.

Question 38

Clonidine

Answer 38

a2 agonist, can be used for hypertensive emergency, ADHD, pain. CNS depression, bradycardia, rebound hypertension, small pupils.

Question 39

a-methyldopa

Answer 39

a2 agonist, used for hypertension in pregnancy. Can cause hemolytic anemia, SLE type syndrome

Question 40

Phenoxybenzamine

Answer 40

Irreversible alpha blocker. Used for pheochromocytoma to prevent hypertensive crisis. Can cause orthostatic hypertension, reflex tachycardia

Question 41

Phentolamine

Answer 41

Reversible alpha blocker

Question 42

Prazosin (-zosin)

Answer 42

a1 blocker, used for BPH, hypertension, PTSD (prazosin). Can cause first dose orthostatic hypotension.

Question 43

Tamsulosin

Answer 43

Selective a1 blocker for prostate, BPH

Question 44

Mirtazapine

Answer 44

Selective a2 blocker, used for depression. Can cause sedation, high cholesterol, increased appetite

Question 45

Effect of each receptor on blood pressure

Answer 45

a1: increases (especially diastolic) b1: increases (especially systolic) b2: decreases (especially diastolic)