Antiemetics

Question 1

Dexamethasone

Answer 1

IND: Off label antiemetic
MOA: Corticosteroid
BOX: NONE
CONTRA: NONE
ADRs: VERY few in short term or only 1-2 doses. GI disturbance, Insomnia, Emotional lability
M/E: NONE

Question 2

ONDASETRON

Answer 2

Zofran
IND: PONV, chemo-induced N/V, radiotherapy N/V
MOA: 5HT3 Receptor antagonist in the CTZ: PREVENTS and TREATS N/V. IV for PONV, sublingual for outpt, and oral solution for kids/babies
MOST prescribed class of antiemetics
BOX:NONE
CONTRA: NONE
ADRs: QT prolongation (caution with other drugs like azithromycin or antipsychotics)
M/E: NONE
Also Palonosetron is used in oncology. Has a longer half life of 40 hours so it is reserved for severe cases.

Question 3

Scopolamine

Answer 3

IND: PREVENTION ONLY. PONV, Motion sickness, hospice for excessive secretions
MOA: Antimuscarinic at M-1 receptors in smooth muscle, secretory glands, and the CNS. 24 hour patch only. 1 hour before Sx/travel or 1 hour post op.
BOX: NONE
CONTRA: Narrow angle glaucoma
ADRs: Xerosomia (dry mouth), drowsy, dizzy, vivid dreams (All anti-muscarinic effects)
M/E: NONE

Question 4

Aprepitant

Answer 4

IND: PREVENTION ONLY. PONV and CINV
MOA: NK1 Receptor antagonist in the CTZ (prevents N/V)
BOX: NONE
CONTRA: NONE
ADRs: Fatigue
M/E: NONE

Question 5

Diphenhydramine

Answer 5

Benadryl
IND: Prevention OR treatment of motion sickness, antitussive, allergies, anaphylaxis, and others. Premed for chemo to prevent N/V and infusion reactions
MOA: Antihistamine. Blocks CTZ and diminishes vestibular stimulation
BOX: NONE
CONTRA: NONE
ADRs: Anticholinergic effects: dry mouth, urine retention, drowsy, sedation, dizzy
M/E: NONE
Dimenhydrinate is the exact same

Question 6

Meclizine

Answer 6

IND: Vertigo, motion sickness treatment and prevention
MOA: antihistamine
BOX: NONE
CONTRA: NONE
ADRs: Same as Diphenhydramine and DIMENHYDRINATE but this one causes the least amount of drowsiness
M/E: NONE

Question 7

Hydroxyzine HCl

Answer 7

Atarax. More often used for pruritis and N/V. DO NOT switch to Hydroxyzine Pamoate.
IND: Anxiety, pruritits, urticaria. Off label for N/V
MOA: Antihistamine and a 5HT2 antagonist/dopamine antagonist in the CNS = anxiolytic effects
BOX:
CONTRA: Early pregnancy, prolonged QT interval
ADRs: Anticholinergic effects
M/E: NONE

Question 8

Hydroxyzine Pamoate

Answer 8

Vistaril. More often used for anxiety. DO NOT switch to Atarax
IND: Anxiety, pruritits, urticaria. Off label for N/V
MOA: Antihistamine and a 5HT2 antagonist/dopamine antagonist in the CNS = anxiolytic effects
BOX:
CONTRA: Early pregnancy, prolonged QT interval
ADRs: Anticholinergic effects
M/E: NONE

Question 9

Metoclopramide

Answer 9

IND: CINV, Gastroparesis, refractory GERD
MOA: Dopamine (D2) and Serotonin (5HT3) receptor antagonist in the CTZ. Also enhances response to acetylcholine in the upper GI = increased motility and gastric emptying and lowers esophageal sphincter tone
BOX: Risk for Tardive Dyskinesia (facial changes) usually with chronic therapy
CONTRA: Mechanical GI obstruction, perforation, or hemorrhage. Seizure disorders. Hx of Tardive Dyskinesia
ADRs: Drowsy, dystonic reactions
M/E: Renal adjustment needed

Question 10

Droperidol

Answer 10

IND: PONV
BOX: Arrhythmias d/t prolonged QT
MOA: Antagonist at D2 receptors. Blocks dopamine in CTZ. Works as an antipsychotic at high doses and an antiemetic at .625-1.25mg
CONTRA: QT Prolongation
ADRs: Orthostatic hypotension
M/E: NONE.

Can also use Haloperidol which takes care of headaches and PONV. Seen more in the ER

Question 11

Prochlorperazine

Answer 11

Compazine
IND: N/V
MOA: D2 Antagonist
BOX: NONE
CONTRA: Coma, large amounts of CNS depressants, peds after Sx, babies (under 2)
ADRs: Constipation, anticholinergic effects, CNS depression
M/E: NONE

Question 12

Promethazine

Answer 12

IND: N/V
MOA: D2A
BOX: Respiratory depression in kids under 2. Severe tissue necrosis, risk of amputation and gangrene with extravasation
CONTRA: under 2. Subcutaneous use. MUST be given large bore and diluted if an IV is necessary. Otherwise, oral tabs and suppositories
ADRs: Respiratory depression, tissue necrosis, drowsy, dizzy
M/E: NONE

Question 13

Dronabinol

Answer 13

IND: Chemo induced N/V, anorexia in pts with AIDS
MOA: Delta 9 THC. Agonist at cannaboid 1 and 2. Causes analgesia, appetite enhancement, muscle relaxing, hormonal actions, and relief of N/V
BOX: NONE, but it is a controlled substance
CONTRA: Concomitant use with disulfiram or metronidazole.
ADRs: Euphoria and abuse potential
M/E: NONE