Antiemetics

Question 1

Dexamethasone (Decadron): glucocorticoid

Answer 1

MOA: unknown, combo with other meds

Complications: adrenal insufficiency, infection, PUD, sodium retention, hypokalemia

interactions: CNS depressants can increase, antihypertensives can increase, anticholinergics can increase, warfarin can decrease, glucocorticoids can increase (same interactions for all)

admin: additional dosing in times of stress, taper before discon, monitor for infection, hyperglycemia, edema, black tarry stools, low K

Question 2

Ondansetron (Zofran): serotonin antagonist

Answer 2

MOA: blocks emesis by blocking serotonin
-chemo, radiation, postop n/v

complications: HA, dizziness, diarrhea, prolonged QT

admin: give 1 hr IV before chemo, give 1 hr PO before anesthesia, admin PO TID for radiation

Question 3

Promethazine (Phenergan), Prochlorperazine (Compazine): dopamine antagonist

Answer 3

MOA: block dopamine
-chemo and postop

complications: EPS (give Benadryl), hypotension, sedation, anticholinergic effects

admin: get orthostatic Bp, pulse rate, RR, and ECG before therapy. Monitor Q and T changes

Question 4

Prokinetic Agents: Metoclopramide (Reglan)

Answer 4

-good for post op and chemo induced n/v
-Oral form for diabetic gastroparesis and GERD
-Extrapyramidal symptoms can be bad give Benadryl
-can be sedating

Question 5

Scopolamine: anticholinergic

Answer 5

MOA: interferes with nerve impulses traveling to inner ear to the brain
-motion sickness

complications: sedation, anticholinergic effects

admin: apply transdermal patch behind ear 4 hrs before travel or take 1 tablet 1 hr before

Question 6

Dimenhydrinate (Dramamine), Hydroxyzine (Atarax/Vistaril): antihistamine

Answer 6

MOA: blocks muscarinic and histaminergic receptors in inner ear and VC
-motion sickness

complications: sedation, anticholinergic effects

Question 7

Lorazepam (Ativan): benzo

Answer 7

MOA: depress nerve function
-combo with other drugs

complications: sedation and complex sleep-related behaviors, paradoxical effects

admin: give with food to prevent GI upset

Question 8

Dronabinol: Cannabinoids

Answer 8

MOA: unknown
-control CINV, increase appetite in AIDS, second-line therapy for those unable to take or nonresponsive to other meds

complications: dissociation, dysphoria, hypotension, tachycardia

admin: for appetite-give before food, for emesis-give every 4 hrs prn