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Flashcards in Intro Pharm Deck (59):
1

Alpha1 receptors

Sympathetic

Linked with Gq proteins

1) Increase vascular smooth muscle contraction
2) Increase pupillary dilator muscle contraction (mydriasis)
3) Increase intestinal and bladder sphincter muscle contraction

2

Alpha2 receptors

Sympathetic

Linked with Gi proteins

1) Lower sympathetic outflow
2) Lower insulin release
3) Lower lipolysis
4) Increase platelet aggregation
5) Lower aqueous humor production

3

B1 receptors

Sympathetic

Linked with Gs proteins

1) Increase HR
2) Increase Contractility
3) Increase renin release
4) Increase Lipolysis

4

B2 receptors

Sympathetic

Linked with Gs proteins

1) Vasodilation
2) Bronchodilation
3) Increase lipolysis
4) Increase insulin release
5) Lower uterine tone (tocolysis)
6) Ciliary muscle relaxation
7) Increase aqueous humor production

5

M1 receptors

Parasympathetic

Linked with Gq proteins

1) CNS
2) Enteric Nervous System

6

M2 receptors

Parasympathetic

Linked with Gi proteins

1) Lower HR
2) Lower contractility of atria

7

M3 receptors

Parasympathetic

Linked with Gq proteins

1) Increase exocrine gland secretions (lacrimal, salivary, gastric acid)
2) Increase gut peristalsis
3) Increase bladder contraction
4) Increase bronchoconstriction
5) Increase pupillary sphincter muscle contraction (miosis)
6) Increase ciliary muscle contraction (accommodation)

8

D1 receptor

Dopamine

Linked with Gs proteins

Relaxes renal vascular smooth muscle

9

D2 receptor

Dopamine

Linked with Gi proteins

Modulates transmitter release, esp in brain

10

H1 receptor

Histamine

Linked with Gq proteins

1) Increased nasal and bronchial mucus production
2) Increased vascular permeability, contraction of bronchioles, pruritis, and pain

11

H2 receptor

Histamine

Linked with Gs proteins

Increases gastric acid secretion

12

V1 receptor

Vasopressin

Linked with Gq proteins

Increase vascular smooth muscle contraction

13

V2 receptor

Vasopressin

Linked with Gs proteins

Increase H2O permeability and reabsorption in collecting tubules of kidney.

14

Bethanechol

Cholinomimetic Direct Muscarinic Agonist

Use: Postoperative ileus, neurogenic ileus, urinary retention

Activates bowel and bladder smooth muscle; resistant to AChE

15

Carbachol

Cholinomimetic - Direct Muscarinic agonist

Use: Constricts pupil and relieves intraocular pressure in glaucoma

Carbon copy of acetylcholine

16

Methacholine

Cholinomimetic - Direct Muscarinic agonist

Use: Challenge test for diagnosis of asthma

Stimulates muscarinic receptors in airway when inhaled

17

Pilocarpine

Cholinomimetic - Direct Muscarinic agonist

Use: Potent stimulator of sweat, tears, and saliva. Open angle and close-angle glaucoma

Contracts ciliary muscle of eye (open-angle glaucoma), pupillary sphincter (closed-angle glaucoma); resistant to AChE

18

Donepezil
Galantamine
Rivastigmine

Cholinomimetic - Indirect muscarinic agonist/ anticholinesterase

Use: Alzheimer

Increase ACh

19

Edrophonium

Cholinomimetic - Indirect muscarinic agonist/ anticholinesterase

Use: Historically, diagnosis of myasthenia gravis (extremely short acting). Myasthenia now diagnosed by anti-AChR Ab (anti-acetylcholine receptor antibody) test.

Increases ACh

20

Neostigmine

Cholinomimetic - Indirect muscarinic agonist/ anticholinesterase

Use: Postop and neurogenic ileus and urinary retention, myasthenia gravis, reversal of neuromuscular junction blockade (postop)

Increases ACh

No CNS penetration

21

Physostigmine

Cholinomimetic - Indirect muscarinic agonist/ anticholinesterase

Use: Anticholinergic toxicity; crosses BBB into CNS

Increases ACh

For Atropine overdose

22

Pyridostigmine

Cholinomimetic - Indirect muscarinic agonist/ anticholinesterase

Use: Myasthenia gravis (long acting); does not penetrate CNS

Increases ACh

Increases muscle strength

23

Cholinomimetic (Muscarinic agonist) cautions

For all of these agents, look out for exacerbation of COPD, asthma, and peptic ulcers when giving to susceptible patients.

24

Cholinesterase inhibitor poisoning

Often due to organophosphates such as parathion that irreversibly inhibit AChE.

Diarrhea
Urination
Miosis
Bronchospasm
Bradycardia
Excitation of skeletal muscle and CNS
Lacrimation
Sweating
Salivation

DUMBBELSS

Organophosphates are often components of insecticides; poisoning usually seen in farmers.

Antidote = atropine (competitive inhibitor) + pralidoxime (regenerates AChE if given early)

25

Atropine
Homatropine
Tropicamide

Muscarinic antagonists/anticholinergics

Act at Eye

Use: Produces mydriasis and cycloplegia

26

Benztropine

Muscarinic antagonists/anticholinergics

Act in CNS

Uses:
Parkinson Disease
Acute dystonia

27

Glycopyrrolate

Muscarinic antagonists/anticholinergics

Acts in GI, respiratory

Uses: Parenteral - preop use to reduce airway secretions
Oral - drooling, peptic ulcer

28

Hyoscyamine
Dicyclomine

Muscarinic antagonists/anticholinergics

GI

Uses:

Antispasmodic for IBS

29

Ipratropium
Tiotropium

Muscarinic antagonists/anticholinergics

Respiratory

Use:

COPD
Asthma

30

Oxybutynin
Solifenacin
Tolterodine

Muscarinic antagonists/anticholinergics

GU

Use:

Reduce bladder spasms and urge urinary incontinence (overactive bladder)

31

Scopolamine

Muscarinic antagonists/anticholinergics

CNS

Use for motion sickness

32

Atropine

Muscarinic antagonist/anticholinergic

Used to treat bradycardia and for ophthalmic applications

Eye: Increases pupil dilation, cycloplegia
Airway: Lowers secretions
Stomach: Lower acid secretion
Gut: Lower motility
Bladder: Lower urgency in cystitis

Toxicity: Increased body temp (due to less sweating); rapid pulse; dry mouth; dry, flushed skin; cycloplegia; constipation; disorientation

Can cause acute-angle closure glaucoma in elderly (due to mydriasis), urinary retention in men with prostatic hyperplasia and hyperthermia in infants

Hot as a hare
Dry as a bone
Red as a beet
Blind as a bat
Mad as a hatter

Jimson weed (datura) leads to gardener's pupil (mydriasis due to plant alkaloids)

33

Tetrodotoxin

Highly potent toxin that binds fast voltage-gated Na channels in cardiac and nerve tissue, preventing depolarization (blocks action potential without changing resting potentials).

Causes nausea, diarrhea, paresthesias, weakness, dizziness, loss of reflexes

Tx is primarily supportive

Poisoning can come from ingestion of poorly prepared pufferfish (fugu), a Japanese delicacy

34

Ciguatoxin

Causes ciguatera fish poisoning. Opens Na channels causing depolarization

Symptoms easily confused with cholinergic poisoning

Temperature-related dysesthesia (cold feels hot; hot feels cold) is regarded as a specific finding of ciguatera

Tx is supportive

Comes from eating reef fish - barracuda, snapper, moray eel

35

Scombroid poisoning

Acute-onset burning sensation of the mouth, flushing of face, erythema, urticaria, pruritis, headache.

May cause anaphylaxis-like presentation (bronchospasm, angioedema, hypotension)

Tx supportively with antihistamines; if needed, antianaphylactics (bronchodilators, Epi)

Caused by consumption of dark-meat fish (bonito, mackerel, mahi-mahi, tuna) improperly stored at warm temps.

Bacterial histidine decarboxylase converts histidine to histamine. Histamine is not degraded by cooking.

Frequently misdiagnosed as allergy to fish

36

Albuterol
Salmeterol

Sympathomimetics - Direct

B2 > B1

Albuterol for acute asthma
Salmeterol for long term asthma or COPD control

37

Dobutamine

Sympathomimetic - Direct

B1 > B2, Alpha

Heart failure (inotropic > chronotropic)
Cardiac stress testing

38

Dopamine

Sympathomimetic - Direct

D1 = D2 > B > alpha

Unstable bradycardia
HF
Shock
Inotropic and chronotropic alpha effects predominate at high doses

39

Epinephrine

Sympathomimetic - Direct

B > alpha

Anaphylaxis
Asthma
Open-angle glaucoma

Alpha effects predominate at high doses

Significantly stronger effect at B2 receptor than NE

40

Isoproterenol

Sympathomimetic - Direct

B1 = B2

Electrophysiologic evaluation of tachyarrhythmias. Can worsen ischemia

41

Norepinephrine

Sympathomimetic - Direct

Alpha1 > alpha2 > B1

Hypotension (but lowers renal perfusion)

Significantly weaker effect at B2-receptor than Epi

42

Phenylephrine

Sympathomimetic - Direct

Alpha1 > alpha2

Hypotension (vasoconstrictor)
Ocular procedures (mydriatic)
Rhinitis (decongestant)

43

Amphetamine

Sympathomimetic - Indirect

Indirect general agonist, reuptake inhibiter, also releases stored catecholamines

For: Narcolepsy, obesity, ADHD

44

Cocaine

Sympathomimetic - Indirect

Indirect general agonist, reuptake inhibiter

Causes vasoconstriction and local anesthesia. Never give B-blockers if cocaine intoxication is suspected (can lead to unopposed alpha 1 activation and extreme hypertension)

45

Ephedrine

sympathomimetic - Indirect

Indirect general agonist, releases stored catecholamines

Nasal decongestion, urinary incontinence, hypotension

46

Clonidine

Alpha 2 agonist

For: hypertensive urgency (limited situations); does not decrease renal blood flow

ADHD

Tourette Syndrome

Toxicity: CNS depression, bradycardia, hypotension, respiratory depression, miosis

47

Alpha-methyldopa

Alpha 2 agonist

For: HTN during pregnancy

Toxicity: Direct Coombs (+) hemolysis
SLE-like syndrome

48

Nonselective alpha blockers

Phenoxybenzamine (irreversible)
Phentolamine (reversible)

49

Phenoxybenzamine

Nonselective alpha blocker (irreversible)

Uses:
Pheochromocytoma (used preop) to prevent catecholamine (hypertensive) crisis

Side effects:
Orthostatic hypotension, reflex tachycardia

50

Phentolamine

Nonselective alpha blocker (reversible)

Uses:
Give to patients on MAOIs who eat tyramine-containing foods

Side effects:
Orthostatic hypotension, reflex tachycardia

51

Alpha 1 selective alpha blockers

Prazosin
Terazosin
Doxazosin
Tamsulosin

52

Prazosin
Terazosin
Doxazosin
Tamsulosin

Alpha 1 selective alpha blockers

Uses:
Urinary symptoms of BPH; PTSD (prazosin); HTN (not tamsulosin)

Side effects:
1st dose orthostatic hypotension, dizziness, HA

53

Alpha 2 selective alpha blockers

Mirtazapine

54

Mirtazapine

Alpha 2 selective alpha blocker

Uses:
Depression

Side effects:
Sedation, high serum cholesterol, high appetite

55

B1 selective antagonists

B1 > B2

Acebutolol (partial agonist)
Atenolol
Betaxolol
Esmolol
Metoprolol

56

Nonselective Beta antagonists

B1 = B2

Nadolol
Pindolol (partial agonist)
Propranolol
Timolol

57

Nonselective Beta and Alpha antagonists

Carvedilol
Labetalol

58

Nebivolol

Combines cardiac-selective B1-adrenergic blockade with stimulation of B3 receptors, which activate NO synthase in the vasculature

59

Beta Blockers

Uses:
1) Angina pectoris - lower HR and contractility, resulting in lower O2 consumption

2) MI - B-blockers (metoprolol, carvedilol, bisoprolol) lower mortality

3) SVT (metoprolol, esmolol) - lower AV conduction velocity (class 2 antiarrhythmics)

4) HTN - lower Cardiac Output, lower renin secretion (due to B1 receptor blockade on JGA cells)

5) HF - lower mortality in chronic HF

6) Glaucoma (timolol) - lower secretion of aqueous humor

Toxicity:

Impotence
CV adverse effects (bradycardia, AV Block, HF)
CNS adverse effects (seizures, sedation, sleep alterations)
Dyslipidemia (metoprolol)
Asthma/COPD exacerbations

Avoid in cocaine users due to risk of unopposed alpha-adrenergic receptor agonist activity

Despite theoretical concern of masking hypoglycemia in diabetics, benefits likely outweigh risks; not contraindicated