S09C75 - Nausea and Vomiting

Question 1

Receptors involved in triggering emesis:

Answer 1

• dopamine/5-HT3 (digoxin, opiates, chemo)
• H1/M1 (uremia, DKA, hypercalcemia)
• vasopressin (Hyperemesis gravidum)

-peripheral 5-HT3 (ASA, erythromycin, copper, ipecac, staphylococcus toxin, GI distension, chemo, radiation, inflm from cholecystitis)

-vestibular: H1 motion, M1 labrynthitis/BPV/meniere's
-
-5-HT3 = serotonin
-H1=histamine
-M1 = muscarine

Question 2

Broad differential for n/v

Answer 2

VINDICATE

• GI: functional (IBS), obstructive, organic (appy, cholecystitis)
• Neuro: stroke, trauma, mass, meningitis, migraine…
• Infxs: bacterial, PNA, SBP, UTI, viral
• Meds/toxins
• Endocrine: pregnancy, DKA, parathyroid d/o, uremia, hyponatremia
• Misc: MI, acute glaucoma, nephrolithiasis, pain, psyc

Question 3

Antiemetics

Answer 3

Antihistamines: benadryl, meclizine (antivert), gravol
-use in migraines and vertigo

Benzodiazepines: sedation, chemo adjunct

Haldol

Corticosteroids - good for chemo-induced n/v

Serotonin antagonists: zofran

Prochlorperazine - for migraines, vertigo, motion sickness, be aware of EPS/NMS/blood dyscrasias/cholestatic jaundice

Maxeran - good for gastroparesis, beware of EPS