Anti-Emetics MCQ Q&A Updated 2024/2025 Solved 100%
Name 2 phenothiazines. What receptors do they block?
Promethazine (Phenergan)-D2 blockade in CTZ + H1
Prochlorperazine (Compazine)-D2 blockade
Name an anti-cholinergic anti-emetic? What kind of nausea is it good for?
Scopolamine (Transderm Scop)
Patch
Good for vertigo/motion sickness/vestibular surgery
Blocks M receptors in vestibular system
Apply patch evening before surgery or 4h before
Which phenothiazine has a black box warning? What is it for?
Promethazine (Phenergan) -Black box warning for tissue damage if IV admin
Major S/E of dopamine anatgonists (Phenothiazines)?
EPS is the most severe
Also have some anticholinergic activity
Compazine (Prochlorperazine) can cause hypotension
Phenergan (Promethazine) can cause sedation
Name two antihistamine anti-emetics and what kind of nausea/vomiting are they
good for?
Hydroxyzine (Atarax)
Dimenhydrinate (Dramamine)
OTC
H1 blockade in the vestibular apparatus & vomiting center
Give after starting anesthesia
Good for vestibular type surgery, motion sickness, vertigo induced vomiting
Drowsiness, Anticholinergic S/E
Don't give Atarax during pregnancy
Droperidol (Inapsine) is what class of anti-emetic?
Antidopaminergic
D2 blockade in the CTZ
Butyrophenone class
Give at end of surgery
Can cause drowsiness, hypotension, reflex tachycardia
What is the black box warning for Droperidol (Inapsine)?
QT interval prolongation
Torsades
What are the 3 classes of antidopaminergic anti-emetics?
Phenothiazines
Butyrophenone
Benzamide
Metoclopramide (Reglan) works on which receptors?
, Benzamide Anti-dopaminergic
Central D2 antagonist in the CTZ
Works peripherally in the GI tract as well
So....good for visceral vagal induced vomiting (toxins, GI distention, infection, mucosal
irritation by targeting the D2 receptors in the GI as well, but serotonin receptors
dominant more than D2 receptors in GI so serotonin antagonists would work better for
this kind of NV)
What is the black box warning for Metoclopramide (Reglan)?
Tardive Dyskinesia-involuntary movements of the perioral area (tongue, mouth, jaw,
eyelids, or face)
Long term use or discontinuation of antidopaminergic anti-emetics can cause
what side effects?
Extrapyramidal Symptoms
(EPS)
Akathisia: motor restlessness
Acute Dystonia: spasmodic contractures producing trismus, torticollis
Pseudo-parkinsonism
Tardive Dyskinesia (TD) involuntary movements of perioral region
Why do antidopaminergic anti-emetics cause EPS side effects?
A balance between dopamien and acetylcholine is needed for motor control.
Decreasing dopamine (D2 antagonists) causes an imbalance in the ACh levels. In
relative terms, the ACH is high if D2 is low. so you get involuntary motor movements.
This is similar to Parkinson's disease in which there is also a decrease in dopamine.
What should you do if your patient has EPS symptoms with an anti-
dopaminergic?
Remove offending agent
Switch anti-emetic
Admin an Anticholinergic (get the Ach levels down) such as:
Diphenhydramine
Benztropine (BEST)
Which phenothiazine has greater anti-cholinergic effects: Proclorperazine
(Compazine) or Promethazine (Phenergan)?
Proclorperazine (Compazine) > Anti-Ach effects so less severe EPS S/E compared to
the other phenothiazine: Promethazine (Phenergan)
When you increase the anti-emetic (D2 antagonism) potency you decrease the
anticholinergic effects which ________ (increases/decreases?) the EPS severity.
Increases EPS if Decreased Anti-cholinergic effects
(Low dopamine, high ACh, = EPS (parkinson like sx))
What corticosteroid is thought to be a prostaglandin antagonist and can be used
as an anti-emetic (admin prior to anesthesia)?
Name 2 phenothiazines. What receptors do they block?
Promethazine (Phenergan)-D2 blockade in CTZ + H1
Prochlorperazine (Compazine)-D2 blockade
Name an anti-cholinergic anti-emetic? What kind of nausea is it good for?
Scopolamine (Transderm Scop)
Patch
Good for vertigo/motion sickness/vestibular surgery
Blocks M receptors in vestibular system
Apply patch evening before surgery or 4h before
Which phenothiazine has a black box warning? What is it for?
Promethazine (Phenergan) -Black box warning for tissue damage if IV admin
Major S/E of dopamine anatgonists (Phenothiazines)?
EPS is the most severe
Also have some anticholinergic activity
Compazine (Prochlorperazine) can cause hypotension
Phenergan (Promethazine) can cause sedation
Name two antihistamine anti-emetics and what kind of nausea/vomiting are they
good for?
Hydroxyzine (Atarax)
Dimenhydrinate (Dramamine)
OTC
H1 blockade in the vestibular apparatus & vomiting center
Give after starting anesthesia
Good for vestibular type surgery, motion sickness, vertigo induced vomiting
Drowsiness, Anticholinergic S/E
Don't give Atarax during pregnancy
Droperidol (Inapsine) is what class of anti-emetic?
Antidopaminergic
D2 blockade in the CTZ
Butyrophenone class
Give at end of surgery
Can cause drowsiness, hypotension, reflex tachycardia
What is the black box warning for Droperidol (Inapsine)?
QT interval prolongation
Torsades
What are the 3 classes of antidopaminergic anti-emetics?
Phenothiazines
Butyrophenone
Benzamide
Metoclopramide (Reglan) works on which receptors?
, Benzamide Anti-dopaminergic
Central D2 antagonist in the CTZ
Works peripherally in the GI tract as well
So....good for visceral vagal induced vomiting (toxins, GI distention, infection, mucosal
irritation by targeting the D2 receptors in the GI as well, but serotonin receptors
dominant more than D2 receptors in GI so serotonin antagonists would work better for
this kind of NV)
What is the black box warning for Metoclopramide (Reglan)?
Tardive Dyskinesia-involuntary movements of the perioral area (tongue, mouth, jaw,
eyelids, or face)
Long term use or discontinuation of antidopaminergic anti-emetics can cause
what side effects?
Extrapyramidal Symptoms
(EPS)
Akathisia: motor restlessness
Acute Dystonia: spasmodic contractures producing trismus, torticollis
Pseudo-parkinsonism
Tardive Dyskinesia (TD) involuntary movements of perioral region
Why do antidopaminergic anti-emetics cause EPS side effects?
A balance between dopamien and acetylcholine is needed for motor control.
Decreasing dopamine (D2 antagonists) causes an imbalance in the ACh levels. In
relative terms, the ACH is high if D2 is low. so you get involuntary motor movements.
This is similar to Parkinson's disease in which there is also a decrease in dopamine.
What should you do if your patient has EPS symptoms with an anti-
dopaminergic?
Remove offending agent
Switch anti-emetic
Admin an Anticholinergic (get the Ach levels down) such as:
Diphenhydramine
Benztropine (BEST)
Which phenothiazine has greater anti-cholinergic effects: Proclorperazine
(Compazine) or Promethazine (Phenergan)?
Proclorperazine (Compazine) > Anti-Ach effects so less severe EPS S/E compared to
the other phenothiazine: Promethazine (Phenergan)
When you increase the anti-emetic (D2 antagonism) potency you decrease the
anticholinergic effects which ________ (increases/decreases?) the EPS severity.
Increases EPS if Decreased Anti-cholinergic effects
(Low dopamine, high ACh, = EPS (parkinson like sx))
What corticosteroid is thought to be a prostaglandin antagonist and can be used
as an anti-emetic (admin prior to anesthesia)?
