Symptom Based Treatment - N/V

Question 1

Antihistamines (H1 histamine receptor antagonists)

for motion sickness
inner ear disease
opioid induced nausea
pregnancy induced emesis

Answer 1

Meclizine 25-100 mg q6-q12

Promethazine 12.5 - 25 mg PO/PR/IV/IM q4-q6

*may cause sedation, confusion, disorientation and extrapyramidal symptoms

Question 2

Anticholinergics
block acetylcholine in central and peripheral nervous system inhibiting parasympathetic impulses

motion sickness
inner ear disease

Answer 2

Scopolamine

• dry mouth, drowsiness, dizziness, blurred vision and disorientation
• withdrawal symptoms if used > 3 days

Question 3

Antidopaminergics
block dopamine receptors in CNS

for medication, toxin or metabolic induced emesis

Answer 3

Metoclopramide
Prochlorperazine

*may cause dysphoria, extrapyramidal symptoms, galactorrhea and reduced libido

Question 4

Serotonin antagonists
5 HT3 receptor antagonists

for chemotherapy and radiation induced emesis
postoperative emesi

Answer 4

Ondasetron 8 mg 30 min before chem then q12

• may cause headache, malaise or constipation

Question 5

Tricyclic antidepressants

for functional vomiting, chronic idiopathic nausea, cyclic vomiting syndrome

Answer 5

Amitriptyline 25-50 PO at night

*causes dry mouth, drowsiness, dizziness, blurred vision and disorientation

Question 6

Glucocorticoids

for chemotherapy induced emesis
post operative nausea

Answer 6

Dexamethasone 4-8 mg 30 mins before chemotherapy