Review of Dopamine Antagonists for Nausea and Vomiting in Palliative Care Patients.

Symptoms of nausea and vomiting are common in palliative care and hospice patients. One of the many classes of medications used for the treatment of nausea and vomiting is dopamine receptor antagonists which are particularly helpful for treating nausea mediated by the chemoreceptor trigger zone (CTZ) and impaired gastrointestinal function. While dopamine antagonists can be very effective treatments for nausea they should be used with caution as they carry the risk of QTc prolongation, have a FDA black box warning for tardive dyskinesia (TD), and increased risk of precipitating psychosis and death in patients with dementia. This review will cover haloperidol, olanzapine, prochlorperazine, and metoclopramide for treatment of nausea and vomiting including evidence of efficacy, pharmacokinetics, and pharmacodynamics to improve safe and effective utilization in clinical practice. This includes medication receptor site affinities at histaminic, muscarinic, serotonergic, and alpha-adrenergic receptors which can help providers anticipate potential adverse effects and risk of extrapyramidal symptoms (EPS), TD, and QTc prolongation. This review also includes considerations for dose adjustments based on renal function, hepatic function, and age. Understanding the pharmacology of dopamine antagonists can help providers choose the best treatment for control of nausea and vomiting and subsequently improve patients' quality of life.