Nausea

Question 1

Prochlorperazine

Answer 1

MOA: Central dopamine receptor antagonist in Chemical trigger zone

-Peripherally blocks vagus nerve

Indications:
-opioid related nausea and vomiting
-GI disorders, inflammation, infection (ie gastroenteritis)
(Not the strongest)

Adverse effects:

• extrapyramidal effects
• dystonic reaction

Question 2

Metoclopramine

Answer 2

MOA:
Dopamine receptor antagonist

Indications
-chemotherapy induced nausea and vomiting
-less emetogenic agents
(more potent)

Adverse Effects:
Extrapyramidal 
-tardive dyskinesia (black box warning) 
-dystonia, akathisia, parkinsonism
-caution with parkinson's disease 
Acute dystonic reactions
-trismus, torticollis
-treated with anticholinergic 
(Don't give for more than 2 weeks at a time)

Question 3

How does metoclopramide also treat upper GI tract dysmotility? What is it used for?

Answer 3

Dopamine receptors inhibit cholinergic smooth muscle stimulation

1. blockade of this effect= primary prokinetic action
2. increases pressure of lower esophageal sphincter
   * **3. increases gastric emptying

Treats:
Diabetic gastroparesis
Gastric stasis

Question 4

Ondansetron (zolfran)

Answer 4

MOA:
Serotonin (5HT3) receptor antagonist
(very potent)

Clinical indication:

• chemo induced nausea/vomiting and prophylaxis
• radiation induced nausea/vomiting and prophylaxis
• post operative nausea/vomiting

SE:
QT prolongation
headache

Question 5

Promethazine

Answer 5

Histamine (H1) receptor antagonist

Indications:
motion sickness treatment and prevention

Adverse effect:
sedation

Question 6

Scopolamine

Answer 6

MOA
pure anticholinergic

Clinical Indications:
Motion sickness

Adverse effects:
confusion
urinary retention 
acute narrow angle glaucoma
dry mouth

Question 7

Corticosteroids

-prednisone, dexamethasone

Answer 7

Indication:

Nausea due to increased cranial pressure

Question 8

Benzodiazepines

Lorazepam, diazepam

Answer 8

Indication:
anxiety associated nausea and vomiting
-anticipatory nausea/vomiting