Anti-Nausea Pharm Flashcards

1
Q

What is the most effective way of treating N/V?

A

TREAT THE CAUSE, not the symptom

if not treat if prophylactically

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2
Q

What are common causes of nausea/vomiting?

A
  • Chemo/radiation (CINV/RINV)
  • post-operative (PONV)
  • pregnancy (NVP)
  • vestibular
  • GI obstruction
  • pharmacologic/metabolic/infectious irritants
  • brain lesions
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3
Q

What are the main classes of antiemetics?

A

Main:

  • serotonin receptor antagonists
  • neurokinin (NK1) receptor antagonists
  • histamine (H1) receptor antagonists
  • dopamine (D2) receptor antagonists
  • muscarinic (M1) receptor antagonists
  • cannabinoid receptor agonists

also of note:

  • glucocorticoids
  • benzodiazepines
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4
Q

How does the mechanism of action of antiemetic cannabinoids differ from the other classes of antiemetics?

A

they are the only agonsts

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5
Q

What are important sites of action for antiemetics?

What antiemetics act there?

A

Chemoreceptor trigger zone (CZT):

  • dopamine (D2)
  • neurokinin (NK1/substance P)
  • serotonin (5-HT3)

Vomiting center (VC):

  • histamine (H1)
  • dopamine (D2)
  • neurokinin (NK1/substance P)
  • serotonin (5-HT3)

GI/enteric nervous system:

-serotonin (5-HT3)

Vestibular system:

  • muscarinic (M1) **only place of note for this mechanism**
  • histamine (H1)
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6
Q

What is the common suffix of serotonin receptor antagonists?

What are the main drugs in the class?

A

-setron

Drugs:

  • dolasetron
  • granisetron
  • ondansetron (Zofran)
  • palonosetron
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7
Q

What is the antiemetic strength of serotonin receptor antagonists?

A

strong anitemetic

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8
Q

Where do serotonin receptor antagonists act?

A
  • vagus nerve
  • area postrema (chemoreceptor trigger zone, CTZ) where the brain detects nauseating substance in the blood
  • GI tract (enterochromafin cells release 5-HT)
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9
Q

What are the general indications for serotonin receptor antagonist use?

A

most causes of N/V

  • CINV/RINV
  • PONV
  • NVP
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10
Q

What serotonin receptor antagonist is not indicated for N/V?

What is the condition it is indicated for?

A

alosetron (indicated for IBS related diarrhea)

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11
Q

What is important about the route of administration for serotonin receptor antagonists?

A
  • oral forms
  • most of them have an IV forms which is important if the nausea is bad enough that people can’t keep oral meds down
  • some have transdermal or SubQ avaliability
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12
Q

What are possible adverse effects of serotonin receptor antagonists?

A

Common:

  • mild CNS symptoms (HA and dizziness)
  • mild GI symptoms (constipation)

Worrisome:

  • dose-dependent QT prolongation (Torsade’s)
  • serotonin syndrome (rigidity, tremor, hyperthermia, confusion)
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13
Q

What are the general pharmacokinetic features of serotonin receptor antagonists?

A

-short half-lives

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14
Q

What serotonin receptor antagonists deviate from the general pharmacokinetics of the class?

A
  • palonosetron - long half-life
  • granisetron - sustained-release formulation (transdermal patch)
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15
Q

What drugs and conditions cause interactions with serotonin receptor antagonists?

A
  • antiarrhythmics/QT prolonging agents -> Torsade’s
  • hypokalmeia/magnesemia -> Torsade’s
  • serotonergic drugs -> serotonin syndrome
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16
Q

What is the common suffix of neurokinin receptor antagonists?

What are the main drugs in the class?

A

-pitant

Drugs:

  • aprepitant
  • fosaprepitant
  • netupitant
  • fosnetupitant
  • rolapitant
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17
Q

What is the antiemetic strength of neurokinin receptor antagonists?

A

moderate antiemetic

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18
Q

Where do neurokinin receptor antagonists act?

A
  • CTZ
  • VC
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19
Q

What are the general indications for neurokinin receptor antagonist use?

A

-CINV

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20
Q

What neurokinin receptor antagonist has an antiemetic indication beyond CINV?

What is the condition?

A

aprepitant (indicated for prophylaxis of PONV in addition to CINV)

prep them for surgery

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21
Q

What are possible adverse effects of neurokinin receptor antagonists?

A
  • CNS symptoms
  • GI symptoms
  • CYP450 inhibition -> drug interactions
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22
Q

What are pharmacokinetic/dynamic features of neurokinin receptor antagonists?

A
  • many have drug/pro-drug forms (“fos-” indicates prodrug form)
  • some have active metabolites -> longer half-lives (netupitant/rolapitant)
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23
Q

What are the main drugs in the histamine (H1)​ receptor antagonist class?

A
  • diphenydramine (benadryl)
  • dimenhydramine (active as is but also metabolized to diphenydramine)
  • hydroxyzine
  • promethazine
  • meclizine
  • cyclizine
  • doxylamine
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24
Q

What is the antiemetic strength of histamine (H1) receptor antagonists?

A

weak antiemetic (not original intended use)

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25
Q

Where do histamine (H1) receptor antagonists act?

A
  • VC
  • vestibular system
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26
Q

What are the general indications for histamine (H1) receptor antagonist use?

A
  • motion sickness/vertigo
  • PONV
  • mild, idiopathic N/V
  • add-on for CINV/RINV (not first line)
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27
Q

What histamine (H1) receptor antagonists are indicated for motion sickness/vertigo ONLY?

A
  • meclizine
  • cyclizine
28
Q

What histamine (H1) receptor antagonist is the first line therapy for NVP?

A

Doxylamine w/ Pyridoxine (B6)

give them a Dr. Pepper (DP)

29
Q

What are possible adverse effects of histamine (H1) receptor antagonists?

A

Anticholinergic effects:

  • CNS depression
  • dry mouth
  • constipation
  • urinary retention
  • blurred vision
  • hypotension
30
Q

What drug interactions occur with histamine (H1) receptor antagonists?

A
  • anticholinergics (worsens anticholinergic adverse effects)
  • other drugs with anticholinergic effects
31
Q

What are the main drugs in the dopamine (D2) receptor antagonist class?

A

Phenothiazines:

  • chlorpromazine
  • prochlorperazine (Compazine)
  • perphenazine

Other:

  • metoclopramide (Reglan)
  • some other medications that are primarily used as psychotics w/ off-label antiemetic use
32
Q

What is the antiemetic strength of dopamine (D2) receptor antagonists?

A

weak/moderate antiemetics (most were oringinally used as antipsychotics)

33
Q

Where do antiemetic dopamine (D2) receptor antagonists act?

A

-CTZ

34
Q

What are the general indications for dopamine (D2) receptor antagonist use?

A
  • mild, idiopathic N/V
  • PONV
  • NVP
  • CINV/RINV (only in combination)
35
Q

What dopamine (D2) receptor antagonist is also indicated for gastroparesis/GI dysmotility?

A

-metoclopramide (Reglan); ACh actions in GI system -> stimulates motility

36
Q

What are possible adverse effects of dopamine (D2) receptor antagonists?

A

Anticholinergic effects:

  • CNS depression
  • dry mouth
  • constipation
  • urinary retention
  • blurred vision
  • hypotension
  • arrhythmia
37
Q

What drugs interactions occur with dopamine (D2) receptor antagonists?

A
  • anticholinergics (worsens anticholinergic adverse effects)
  • other drugs with anticholinergic effects
  • antiarrhythmics (QT-prologing agents)
  • antihypertensives
38
Q

What contraindication does metoclopramide have in addition to those of other dopamine receptor antagonists?

A

-GI obstruction (due to its prokinetic effects)

39
Q

What are the main antiemetic drugs in the muscarinic (M1) receptor antagonist class?

A
  • scopolamine
  • glycopyrrolate
40
Q

What is the antiemetic strength of muscarinic (M1) receptor antagonists?

A

-weak antiemetic (treat motion sickness which can cause N/V)

41
Q

Where do antiemetic muscarinic (M1) receptor antagonists act?

A
  • vestibular system
  • muscarinic receptors throughout the brain
42
Q

What are the general indications for antiemetic muscarinic (M1) receptor antagonist use?

A
  • motion sickness
  • excessive secretions in end-of-life care
43
Q

What is important about the route of admission for muscarinic (M1) receptor antagonists?

A

scopolamine comes in as a transdermal patch -> works for 72 hours

44
Q

What are possible adverse effects of muscarinic (M1) receptor antagonists?

A

Significant anticholinergic effects (it is an anticholinergic itself):

  • CNS depression
  • dry mouth
  • constipation
  • urinary retention
  • blurred vision
45
Q

What drugs interactions occur with muscarinic (M1) receptor antagonists?

A

-anticholinergics

46
Q

What are the main antiemetic drugs in the cannabinoid receptor agonist class?

A
  • dronabinol
  • nabilone
47
Q

What is the antiemetic strength of cannabinoid receptor agonists?

A

strong antiemetic

48
Q

Where do antiemetic cannabinoid receptor agonists act?

A

CB1 and CB2 receptors in VC and CTZ

49
Q

What are the general indications for antiemetic cannabinoid receptor agonist use?

What is special about their indications?

A

-treatment-resistant CINV only (they are schdule II/III drugs and useage is restricted)

50
Q

What are the general pharmacokinetic features of cannabinoid receptor agonists?

(what is unique to each drug)

A

Both act rapidly and are long lasting (active metabolites)

Dronabinol:

  • large first pass effect
  • only one active metabolite

Nabilone:

-many active metabolites

51
Q

What are possible adverse effects of cannabinoid receptor agonists?

A
  • emotional lability
  • vertigo
  • sedation
  • impaired cognition
  • hallucinations
  • dry mouth
  • appetite stimulation
  • increased HR/BP (sympathomimetic)
52
Q

What drugs interactions occur with cannabinoid receptor agonists?

A
  • CNS depressants
  • cardiovascular agents
  • sympathomimetics
53
Q

What are the categories of emetic potential of chemotherapeutics?

A
  • high (>90%)
  • moderate (30-90%)
  • low (10-30%)
  • minimal (<10%)
54
Q

What are the classifications of CINV treatment?

A
  • acute (<24 hours following chemo administration)
  • chronic (>24 hours following chemo administration)
  • anticipatory (given prior to chemo administration
55
Q

What is the treatment regimen for high emetogenic CINV?

A

3-drug regimen:

  • neurokinin receptor antagonist
  • serotonin receptor antagonist
  • corticosteroid (dexamethasone)
  • above for a minimum of 3 days of chronic treatment
  • anticipatory treatment (all cases)
  • breakthrough treatment (as need)
56
Q

How can high emetogenic CINV treatment be altered if unsuccessful?

A

Increase to 4-drug regimen:

  • add olanzapine (D2 antagonist)
  • or-
  • can add a cannabinoid if resistant to treatment
57
Q

What is the treatment regimen for moderate emetogenic CINV?

A

2-drug regimen:

  • serotonin receptor antagonist
  • corticosteroid (dexamethasone)
  • above for a minimum of 2 days of chronic treatment
  • anticipatory treatment (all cases)
  • breakthrough treatment (as need)
58
Q

How can moderate emetogenic CINV treatment be altered if unsuccessful?

A

Increase to 3-drug regimen:

-add NK1 antagonist -or- olanzapine (D2 antagonist)

59
Q

What is the treatment regimen for low emetogenic CINV?

A

1-drug regimen (one of the below):

  • **corticosteroid (dexamethasone) -or-
  • **serotonin receptor antagonist -or-
  • metoclopramide (Reglan) -or-
  • prochlorperazine​
  • above for a minimum of 1 day of acute treatment
  • anticipatory treatment (all cases)
  • breakthrough treatment (as need)
60
Q

What is the treatment regimen for low emetogenic CINV?

A

1-drug regimen (one of the below):

  • corticosteroid (dexamethasone) -or-
  • serotonin receptor antagonist -or-
  • metoclopramie (Reglan) -or-
  • prochloperazine
  • above for a minimum of 1 day of acute treatment
  • anticipatory treatment (all cases)
  • breakthrough treatment (as need)
61
Q

What is the treatment regimen for minimal emetogenic CINV?

A

No routine drug regimen

  • anticipatory treatment (all cases)
  • breakthrough treatment (as need)
62
Q

What are the main antiemetic drugs used to treat motion sickness?

A
  • scopolamine
  • dimenhydrinate
  • meclizine
63
Q

What are the main antiemetic drugs used to treat vertigo?

A
  • meclizine
  • cyclizine

*both H1 receptor antagonists

64
Q

What are the main antiemetic drugs used to treat gastroparesis?

A

-metoclopramide

65
Q

What are the main antiemetic drugs used to treat NVP?

A
  • doxylamine w/ pyrioxidine (B6)
  • 5HT3 antagonist
  • D2 antagonist