CNS drugs

Question 1

Alpha 2 receptor

Answer 1

Sympathetic

Gi

Decreased sympathetic outflow (also decreased insulin, decreased aqueous humor)

Question 2

Beta 1 receptor

Answer 2

Sympathetic

Gs

Increased HR, contractility, renin, lipolysis

Question 3

Beta 2 receptor

Answer 3

Sympathetics

Gs

Vasodilation, bronchodilation, lipolysis, ciliary muscle relaxation (pupil dilation), increased insulin, decreased uterine tone, increased aqueous humor prodn

Question 4

M1 receptor

Answer 4

Parasympathetic

Gq

CNS, enteric NS

Question 5

M2 receptor

Answer 5

Parasymp

Gi

In heart – decreased HR and contractility

Question 6

M3 receptor

Answer 6

Parasympathetic

Gq

Everywhere that’s not heart or CNS - increased gland secretions, increased bladder contraction, bronchoconstriction, pupil constriction (contract pupillary sphincter) and ciliary muscle constriction (accommodation)

Question 7

Dopamine receptor on renal vascular smooth muscle

Answer 7

D1 (Gs)

Question 8

Vasopressin receptors

Answer 8

V1 (Gq) - increased vasc smooth muscle contraction

V2 (Gs) - increased H2O permeability and reabs in collecting tubules of kidney

Question 9

Cholinomimetic agents

Answer 9

Direct:

Bethanechol - move bowel and bladder

Carbachol - constrict pupil and treat glaucoma

Methacholine - challenge test for asthma (causes bronchocon)

Pilocarpine - stimulate sweat, tears, saliva, treat glaucoma

Indirect:

Anticholinesterases (donepezil, galantamine, rivastigmine (AD), edrophonium (diagnose MG), neostigmine (treat MG, treat ileus and urinary retention, reverse NM blockade), physostigmine (reverse atropine overdose b/c crosses BBB), pyridostigmine (treat MG, doesn’t cross BBB)

Question 10

Contraindications for cholinomimetics

Answer 10

COPD, asthma, peptic ulcers

Question 11

Common cause of cholinesterase inhibitor poisoning + antidote

Answer 11

Organophosphates (eg parathion - insecticide)

antidote = atropine + pralidoxime (binds organophosphate-AChE complex and boots the organophosphate off, recovering AChE)

sx = parasympathetic activation everywhere

Question 12

Muscarinic antagonists

Answer 12

Atropine (treats bradycardia and dilates pupil, decreases gut acid secretion and motility, decreases urgency in cystitis; tox: increased body temp b/c decreased sweating, tachycardia, dry/flushed skin, disorientation, cycloplegia, constipation)

Benztropine (treats PD)

glycopyrrolate (preop to reduce secretions, treat drooling and peptic ulcers - works on GI and resp tracts)

Hyoscyamine, dicyclomine (GI)

Ipratropium, tiotropium (resp - treats COPD, asthma)

oxybutynin, solifenacin, tolterodine (GU, reduce bladder spasms, urgency, incontinence)

Scopolamine (CNS - treat motion sickness)

Question 13

Alpha 1 receptor

Answer 13

Sympathetic

Gq

Increased vasc smooth muscle contraction (increased PVR), mydriasis (pupil dilation from contraction of pupillary dilator), sphincter contraction

Question 14

Tetrodotoxin

Answer 14

Prevents depol by binding Na channels in cardiac and nerve tissue

Pufferfish (Japanese)

–> n/d, weakness, dizziness, loss of reflexes

Question 15

Ciguatoxin

Answer 15

Reef fish

Opens Na channels –> depol (lots of parasympathetic effects + temperature-related dysesthesia [cold feels hot, hot feels cold])

Question 16

Scombroid poisoning

Answer 16

Burning, hives, redness, anaphylaxis-like

From histamine in warm dark-meat fish

Tx: antihistamines

Question 17

Direct sympathomimetics

Answer 17

alpha>beta: NE (treat hypotn)

beta > alpha:
Epi (anaphylaxis, asthma, open-angle glaucoma; alpha predom at high doses)

beta1=beta2: Isoproterenol

beta2>beta1: albuterol, salmeterol (asthma)

beta1>beta2: Dobutamine (treat HF)

alpha1>alpha2: phenylephrine (treat hypotn, dilate pupil, decongestant)

alpha2 (sympatholytics): Clonidine (treat htn without decreasing renal blood flow, ADHD, Tourette), alpha-methyldopa (treat HTN in preg)

Question 18

Indirect sympathomimetics

Answer 18

Amphetamine (general ag, reuptake inhibition, releases stored catechol) - treat narcolepsy, obesity, ADHD

Cocaine (vasocon + local anesthesia)

Ephedrine (general ag, releases stored catechol) - nasal decongestion, urinary incontinence, hypotension

Question 19

Alpha blockers

Answer 19

Nonselective: phenoxybenzamine (irrev - pheo), phentolamine (reversible - treat MAO + tyramine)

alpha1: “-osin” - urinary sx of BPH, PTSD, HTN (can –> orthostatic hypotension)
alpha2: Mirtazapine - treat depression, can –> sedation, increased chol, increased appetite

Question 20

Mirtazapine

Answer 20

Alpha2 blocker

Treats depression

Can –> sedation, increased cholesterol, increased appetite

Question 21

Beta blockers + uses

Answer 21

“-lol”

Used to treat:

• angina pectoris
• MI
• SVT (metoprolol, esmolol)
• HTN
• HF
• Glaucoma (timolol)

Question 22

Beta 1 blockers

Answer 22

Acebutolol (partial ag)
Atenolol
Betaxolol
Esmolol
Metoprolol

Question 23

Nonselective beta blockers

Answer 23

Nadolol, pindolol (partial ag), propanolol, timolol

Question 24

Nonselective alpha and beta blocker

Answer 24

Carvedilol, labetalol

Question 25

Treat overdose of heparin with ___

Answer 25

Protamine sulfate

Question 26

Treat copper, arsenic, gold overdose with ___

Answer 26

Penicillamine

Question 27

Treat cyanide overdose with __

Answer 27

Nitrite + thiosulphate, hydroxycobalamine

Question 28

Treat methanol/ethylene glycol overdose with

Answer 28

Fomepizole > ethanol

Question 29

Treat opioid overdose with ___

Answer 29

Naloxone, naltrexone

Question 30

Alkalinize urine with ___

Answer 30

NaHCO3

Question 31

Acidify urine with

Answer 31

NH4Cl

Question 32

___ drugs can cause dilated cardiomyopathy

Answer 32

Anthracyclines (eg doxorubicin) prevent with dexrazoxane

Question 33

Glycopyrrolate

Answer 33

anti-muscarinic preop to reduce resp secretions also to decrease drooling and treat peptic ulcer

Question 34

hyoscyamine, dicyclomine

Answer 34

anti-muscarinic to decrease gut spasms in IBD

Question 35

ipratropium, tiotropium

Answer 35

antimuscarininc used for COPD and asthma treatment

Question 36

oxybutynin, solifenacin, tolterodine

Answer 36

antimuscarinic decrease bladder spasms and urge incontinence in overactive bladder

Question 37

scopolamine use

Answer 37

antimuscarinic used for motion sickness

Question 38

homatropine, tropicamide

Answer 38

like atropine, antimuscarinic used for pupil dilation etc