Multiple individual pathophysiological pathways which require different approaches
Gastrointestinal Axis
MOA: Distension and inflammation of the GI tract, relaying signals back to the brain. Mediated by serotonin and dopamine receptors
Medications of choice
Anti-dopaminergic agents
Metoclopramide
IV/PO: 5-10mg q6hrs
Max dose: 40mg/d
Slower infusions help avoid adverse effects including extrapyramidal syndromes
Prochloperazine
IV: 2.5-5mg
IM: 5-10mg
Larger side effect profile: alpha blockade, antimuscarinic side effects, sedation from anti-histamine action
Serotonin inhibitors
Ondansetron
IV/PO: 4-8mg q4-6hrs
Adverse effects: QT prolongation
Vestibular Axis
Inner ear dysfunctions: BPPV, orthostasis, Meniere's disease
Mediated by histamine and muscarinic receptors
Medications of choice
Anti-histamines
Diphenydramine
IV/PO: 25-50mg q6hrs
Meclizine
PO: 12.5-25mg q6hrs
muscarinic receptor antagonist
Scopolamine
transdermal patch
Brainstem Mediated
Chemoreceptor trigger zone associated with dopamine, serotonin, muscarinic receptors
Patient presentations: DKA, Hyperemesis gravidarum, chemotherapy, etc.
Medications of choice
Anti-dopaminergic agents
Metoclopramide
IV/PO: 5-10mg q6hrs
Max dose: 40mg/d
Slower infusions help avoid adverse effects including extrapyramidal syndromes
Prochloperazine
IV: 2.5-5mg
IM: 5-10mg
Larger side effect profile: alpha blockade, antimuscarinic side effects, sedation from anti-histamine action
Serotonin inhibitors
Ondansetron
IV/PO: 4-8mg q4-6hrs
Adverse effects: QT prolongation
Direct Chemoreceptor trigger zone actor
Trimethobenzamide
IM/PO: 200mg
Alcohol Swabs
have the patient sniff it
thought to decrease signaling to chemoreceptor trigger zone
Systematic review and meta-analysis reviews isopropyl alcohol has statistically significant reduction in reported nausea by 2.18 points on a 10 point scale (99.6% CI 1.6-2.78)
Brain-Gut Axis
Peripheral hypersensitivity, hyperanalgesia, central dysregulation (brain misreading signals). Thought to be related to close connection between development of central and enteric nervous system (associated with embryonic tissues)
Patient presentations: cyclic vomiting syndrome, cannabinoid hyperemesis
Medications of choice
Anti-dopaminergic agents
Haloperidol
IV/PO: 2-5mg
Droperidol
IV: 1.25-2.5mg
Olanzapine
IV/PO: 5-10mg
Benzodiazepines
Diazepam
IV/PO: 5-10mg
EKG Prior to medication administration?
Not routinely indicated
Identify patients at high risk
Prior EKGs
Patient's current medication lists
Consider EKG if redosing medications
QT Prolongation is typically dose dependent, so the main culprits (droperidol, ondansetron, metoclopramide) are typically safe at lower doses
Asim Shahid, DO
References
Farkas J. Nausea, emesis, and antiemetics. EMCrit Project. Published August 17, 2020. Accessed July 6, 2023. https://emcrit.org/ibcc/antiemetic/
Furyk JS, et al. Drugs for the treatment of nausea and vomiting in adults in the emergency department setting. Cochrane Database Syst Rev. 2015;2015(9):CD010106. Published 2015 Sep 28. PMID: 26411330
Repanshek Z. Vomiting in a World Without Ondansetron Zachary Repanshek, MD FAAEM. www.youtube.com. Published 2018. Accessed July 6, 2023. https://www.youtube.com/watch?v=cewLtoKRzb0
Patanwala AE, et al. Antiemetic therapy for nausea and vomiting in the emergency department. J Emerg Med. 2010;39(3):330-336. PMID: 20022195
M. Camejo, et al. Rethinking Ondansetron as a First Line Agent for Nausea and Vomiting in the Setting of Abdominal Pain and Headache in the Emergency Department, Annals of Emergency Medicine, Volume 78, Issue 4, Supplement, 2021. Link
Egerton-Warburton D, et al. Antiemetic use for nausea and vomiting in adult emergency department patients: randomized controlled trial comparing ondansetron, metoclopramide, and placebo. Ann Emerg Med. 2014;64(5):526-532.e1. PMID: 24818542
Braude D, et al. Antiemetics in the ED: a randomized controlled trial comparing 3 common agents. Am J Emerg Med. 2006;24(2):177-182. PMID: 16490647
Cisewski D. Droperidol Use in the Emergency Department – What’s Old is New Again. emDOCs.net - Emergency Medicine Education. Published August 1, 2019. http://www.emdocs.net/droperidol-use-in-the-emergency-department-whats-old-is-new-again/
Shahsavari D, et al. Haloperidol Use in the Emergency Department for Gastrointestinal Symptoms: Nausea, Vomiting, and Abdominal Pain. Clin Transl Gastroenterol. 2021;12(6):e00362. Published 2021 Jun 1. PMID: 34060494
J. McCoy, et al. Stop the Vomit: Haloperidol as a Superior First-line Antiemetic, Annals of Emergency Medicine, Volume 80, Issue 4, Supplement, 2022. Link