What medication can be given for vomiting to a patient on escitalopram (Selective Serotonin Reuptake Inhibitor)?

Antiemetic Selection for Patients on Escitalopram

Ondansetron (a 5-HT3 antagonist) is the preferred first-line antiemetic for patients taking escitalopram, as it is safe, effective, and does not interact with SSRIs or cause significant sedation or extrapyramidal symptoms. 1, 2

Primary Recommendation: Ondansetron

Ondansetron should be administered at 4-8 mg orally 2-3 times daily, or 8 mg intravenously for acute vomiting. 3, 4 This agent is particularly advantageous because:

• It does not cause sedation or akathisia, unlike dopamine antagonists 1
• It has no known drug interactions with escitalopram or other SSRIs 1, 5
• It demonstrates consistent efficacy across multiple settings, with mean nausea score reductions of 4.0 points on a 10-point scale 2
• It can be administered via multiple routes (IV, oral, or oral dissolving tablet) depending on severity 2

Alternative Dopamine Antagonist Options

If ondansetron is unavailable or ineffective, dopamine receptor antagonists are acceptable alternatives, though they require more careful monitoring: 4, 1

Metoclopramide

• Dose: 10-20 mg orally or IV, 3-4 times daily 4
• Monitor for akathisia that can develop within 48 hours of administration 1
• Reduce infusion rate to minimize akathisia risk 1
• Have IV diphenhydramine available to treat extrapyramidal symptoms if they occur 1

Prochlorperazine

• Dose: 5-10 mg orally or IV, 3-4 times daily 4
• Similar akathisia monitoring requirements as metoclopramide 1
• Less effective than ondansetron but generally well-tolerated 1

Haloperidol

• Dose: 0.5-2 mg orally or IV, 3-6 times daily 4
• Particularly useful for refractory cases 3
• Requires monitoring for extrapyramidal symptoms 4

Important Clinical Considerations

Avoid Promethazine

Promethazine causes significant sedation and carries risk of vascular damage with IV administration, making it a poor choice unless sedation is specifically desired 1

Rule Out Escitalopram as the Cause

Before treating vomiting in a patient on escitalopram, determine if the SSRI itself is causing the symptoms: 6

• Gastrointestinal side effects typically occur during initial treatment or dose increases 6
• These effects are usually transient and resolve with continued treatment 6
• If vomiting is intolerable, evaluate for other potential causes before attributing solely to escitalopram 6

Combination Therapy for Refractory Cases

For breakthrough vomiting not responding to single agents: 3

• Add an agent from a different drug class 3
• Consider dexamethasone 2-8 mg orally or IV as adjunctive therapy 4
• Multiple concurrent agents at alternating schedules may be necessary 3
• Ensure adequate hydration and correct electrolyte abnormalities 3

Common Pitfalls to Avoid

• Do not use droperidol as first-line due to FDA black box warning for QT prolongation; reserve for refractory cases only 1
• Monitor for constipation with 5-HT3 antagonists, which may worsen symptoms in some patients 4
• Assess for drug-drug interactions if using metoclopramide or other dopamine antagonists with multiple medications 1
• Consider non-pharmacologic causes such as gastroesophageal reflux, constipation, or other medications before escalating antiemetic therapy 4