Treatment of SSRI-Induced Nausea and Vomiting

First-Line Therapy

The American Academy of Family Physicians recommends initiating dopamine receptor antagonists, such as metoclopramide 10-40 mg PO/IV every 4-6 hours or prochlorperazine 10 mg PO/IV every 4-6 hours, as first-line therapy for patients experiencing nausea and vomiting while taking SSRIs, due to their efficacy in reducing symptoms 1, 2

The National Comprehensive Cancer Network recommends starting with metoclopramide or prochlorperazine, titrated to maximum benefit and tolerance, with a strength of evidence of high, for the management of nausea and vomiting in patients taking SSRIs 2, 3, 4
Metoclopramide 10-40 mg PO/IV every 4-6 hours is particularly effective for gastric stasis, with a moderate strength of evidence, and is recommended by the National Comprehensive Cancer Network 4, 2
Prochlorperazine 10 mg PO/IV every 4-6 hours or 25 mg rectal suppository every 12 hours is an alternative dopamine antagonist with a different receptor profile, and has a moderate strength of evidence, as recommended by the National Comprehensive Cancer Network 4, 3

The National Comprehensive Cancer Network recommends adding benzodiazepines, such as lorazepam 0.5-2 mg PO/IV every 4-6 hours or alprazolam 0.25-0.5 mg PO three times daily, to address anxiety component and anticipatory nausea, with a low strength of evidence 5, 4, 3
Dexamethasone 4-12 mg PO/IV daily has a modest antiemetic effect, with a low strength of evidence, and is recommended by the National Comprehensive Cancer Network 5, 4

The National Comprehensive Cancer Network recommends administering antiemetics on a scheduled basis rather than PRN, as prevention is far easier than treating established vomiting, with a high strength of evidence 2

The National Comprehensive Cancer Network recommends ensuring adequate fluid intake of at least 1.5 L/day with small, frequent meals, with a moderate strength of evidence, to prevent dehydration and electrolyte imbalances 2
Thiamin supplementation should be added to prevent Wernicke's encephalopathy in patients with persistent vomiting, with a high strength of evidence, as recommended by the National Comprehensive Cancer Network 2

The American Academy of Family Physicians recommends avoiding ondansetron in patients with congenital long QT syndrome, electrolyte abnormalities, or congestive heart failure, due to the risk of serotonin syndrome and other adverse effects, with a high strength of evidence 1

The American Academy of Family Physicians recommends reassessing SSRI therapy if nausea and vomiting persist despite optimal antiemetic therapy, and considering alternative agents, such as SNRIs or other antidepressants, with a moderate strength of evidence 1