(2) Antiemetic/nausea meds

N/V

other drug classes that can be used to treat N/V

• anticholinergic drugs

  • Scopolamine

• antihistamine drugs (motion sickness)

  • Dimenhydrinate

  • Diphenhydramine

  • Hydroxyzine - PO or IM only, never IV

  • Meclizine

Bismuth Subsalicylate

aka, Pepto-Bismol!

• action: suppress vomiting and diarrhea by anti-secretory effects

• admin: available in tablets and liquids; OTC med

• AE:

  • dark stool (expected finding and doesnt indicate GI bleed)

  • dark coloring of tongue

  • metallic taste

• NI:

  • teach pt to report continuted N/V

  • promote hydration

Meclizine

• class: antihistamine

• action: prevent activation of muscarinic and histaminic receptors in the vomiting center and inhibits vestibular stimulation in the middle ear (dizziness, motion sickness)

• AE:

  • drowsiness, dry mouth, urinary retention, constipation (it’s an anticholingeric, so it causes these)

• NI: caution w/ other antihistamine drugs

Scopolamine

• action: anticholinergic effects also works in the middle ear to decrease dizziness. it’s the primary anticholinergic drug used as antiemetic

• used Preoperatively and for Motion Sickness

• admin: Transdermal placed behind ear

• AE: Anticholinergic effects: blurred vision, dry membranes

• Teaching:

  • patch is removed in 72 hrs (24hr for elderly pts)

  • wash hands after application

  • remove if affecting vision

  • promote hydration

Ondansetron (Zofran)

• class: Serotonin Blocker

• action: blocks serotonin in the chemoreceptor trigger zone and vagal fibers in the gut

• uses: General N/V

• admin: IV, IM, PO, and ODT (orally disintegrates on tongue) tablet

  • specific timing recommendations for chemotherapy (given 30-60min prior to start of chemo)

  • usually give Q6h PRN nausea for genral N/V; if IV push, give over 2-5min (give slow to decrease risk of cardiac effects)

• AE: Constipation, headache, dizziness, fatigue, QT prolongation

• CI: QT syndrome, some concerns in pregnancy for cleft palate in fetus if used in 1st trimester

• NI: EKG on any pts w/ cardiac history

Promethazine (Phenergan)

• class: Antidopaminergic Drug (has antidopaminergic as well as antihistaminergic properties) (blocks both dop. and hist. receptors)

• acion: treats N

• admin: IV, IM topical gel, oral, and rectal suppository dosages

  • IV is considered high-alert — *phlebitis*

    • for this reason, it’s best diluted in at least 10mL of fluid

    • typically lasts 4-6hrs

• AE: Anticholinergic effects, EPS, HTN and sedation

• ***BLACK BOX WARNINGS: EPS and severe tissue injury

• CI: Avoid in geriatric pts and pts w/ glaucoma; Not used in children <2 yrs

similar drugs in same class: Compazine

Remember: “azine”

Prochlorperazine (Compazine)

v similar to Phenergan, however, this one is more common

• class: Antidopaminergic (has antidopaminergic as well as antihistaminergic properties)

• admin: Oral, IV, IM; Onset of action typically 30-40min and lasts 3-4hr

• CI: pt w/ a hypersensitivity to phenothiazines, pts in a coma, history of seziures, encephalopathy, or bone marrow suppression

Metoclopramide (Reglan)

• action: increases esophageal sphincter tone to promote gastric emptying (helps prevent reflux)

• use: diabetic gastroparesis, pts w/ tube feedings, refractory nausea(ongoing N/V that dont respond to other antiemetics)

• admin: IV and PO dosing

  • requirs a lower dose in renal failure

  • take w/in 30min of meal

• AE: Sedation, Drowsiness, confusion, diarrhea, EPS

• NI: monitor for diarrhea and hydration

Ginger

• use: N/V, including that caused by chemotherapy, morning sickness, and motion sickness

• AE: anorexia, N/V, skin reactions

• Drug Interactions: may increase absorption of oral meds; Increase bleeding risk w/ anticoags