Antiemetics

• Nausea Causing Medications
  • Aspirin, NSAIDs, Opioids
  • Erythromycin, sulfonamides, Acyclovir
  • Antiarrhythmics, Antihypertensives, Digoxin, Diuretics
  • Contraception, Antidiabetic meds
  • Anticonvulsants, Parkinson’s Disease meds
  • W/U: Residuals
• Selective 5-HT3 Antagonist
  • MOA: Block serotonin receptors in the CNS and GI
    • Works on GI tract primarily, but CNS/PNS also
    • Used in gastroenteritis
    • SE: Headache, constipation, diarrhea, dry mouth, fatigue, Serotonin Syndrome, QTc Prolongation
    • CI: PKU, Hepatic Impairment
  • Ondansetron (Zofran)
    • Dose: 4-8mg Oral, Sublingual, IV over 15 minutes
    • SE: QTc Prolongation, Activating
  • Palonosetron (Aloxi)
    • Dose: 0.25mg IV
    • No QT prolongation, 40 hour half life, better than 8mg zofran
    • SE: Activating
  • Dolasetron
  • Granisetron
    • Oral, IV, Subcutaneous, Transdermal
• Histamine (H1) Receptor Antagonists
  • Notes:
    • Works on CNS (area postrema) and in the vestibular nucleus
    • SE: QTc Prolongation
  • Diphenhydramine (Benadryl)
    • 10-50mg per dose, up to 100mg per dose, 400mg per day
    • Oral, IV, IM
    • SE: QTc Prolongation
    • CI: Acute asthma, GI obstruction, Closed angle glaucoma
  • Meclizine
    • No QTc prolongation
  • Dimenhydrinate
    • No QTc prolongation
  • Cyclizine
  • Mirtazapine (Remeron)
  • Hydroxyzine (Vistaril)
    • Quick acting, short-term, anxiolytic, insomnia
    • SE: sedation, dry mouth, constipation, urinary retention, blurry vision
      • QTc Prolongation
• Phenothiazine
  • Prochlorperazine (Compazine)
    • MOA: D2 antagonism ≥ H1 = M1
    • Dose: 10mg IV
    • Little to no QTc prolongation
    • SE: Extrapyramidal SE, M1 activity
  • Chlorpromazine (Thorazine)
    • MOA: D2 = H1 ≥ M1 ≥ 5HT3
    • Dose: 25mg IV/IM
    • SE: Extrapyramidal SE, QTc Prolongation, M1 activity
  • Promethazine (Phenergan)
    • MOA: H1 ≥ M1 ≥ D2
    • Dose: 12.5-25mg PO/IM
    • SE: Extrapyramidal SE, QTc Prolongation, Most M1 activity
• Butyrophenone
  • Droperidol
    • MOA: D2 Antagonism ≥≥≥ H1
    • Dose: 0.625-2.5 IV, IM
    • SE: QTc Prolongation
  • Haloperidol
    • MOA: D2 Antagonism ≥≥≥ H1
    • Dose: 2-5 mg IV, Oral, IM
    • SE: QTc Prolongation
• Benzamide
  • Metoclopramide
    • MOA: D2 ≥ 5-H3T antagonism, Cholinergic Agonism
    • 10-20mg Oral, IV, IM
    • SE: QTc Prolongation
  • Domperidone
    • MOA: D2 antagonism
    • Oral
    • SE: QTc Prolongation, Headache, Xerostomia
• Antimuscarinic
  • MOA: M1 antagonism
  • Scopolamine
    • Transdermal
    • No QTc Prolongation
    • SE: Xerostomia, Blurry Vision, Fatigue
• Benzodiazepines
  • GABA-A Agonism
  • SE: Anterograde amnesia
  • No QTc Prolongation
  • Lorazepam
    • Oral, Sublingual, IV, IM
  • Alprazolam
    • Oral
• Glucocorticoid
  • Dexamethasone (Decadron)
  • No QTc prolongation
• Neurokinin Receptor Antagonists
  • MOA: NK1 Antagonism
  • No QTc Prolongation
  • Aprepitant
    • Oral
    • SE: CYP3A4 Inhibitor, fatigue, Neutropenia (≥ in children)
  • Fosaprepitant
    • IV
    • SE: CYP3A4 Inhibitor, fatigue, Neutropenia (≥ in children)
  • Netupitant
    • SE: CYP3A4 Inhibitor, fatigue, Neutropenia (≥ in children)
  • Rolapitant
    • SE: CYP2D5 inhibitor, Dizziness
• Dopamine Antagonists
  • SE: muscle spasms, restlessness
  • Olanzapine (Zyprexa)
• Appetite Stimulants (Orexigenic)
  • Dronabinol
  • Mirtazapine (Remeron)
  • Prednisone
  • Megestrol
  • Lithium
  • Insulin