What is the treatment for persistent retching?

Treatment for Persistent Retching

The first-line treatment for persistent retching should include ondansetron (8 mg sublingual/oral every 4-6 hours) or metoclopramide (10-20 mg orally three to four times daily), with additional supportive measures based on the underlying cause. 1, 2

Pharmacological Management

First-Line Antiemetic Options

• Ondansetron (5-HT3 receptor antagonist): 8 mg sublingual/oral every 4-6 hours during episodes of retching 1
• Metoclopramide: 10-20 mg orally three to four times daily, which works through both central and peripheral pathways 2
• Promethazine: 12.5-25 mg oral/rectal every 4-6 hours (note: more sedating than other options) 1
• Prochlorperazine: 5-10 mg every 6-8 hours or 25 mg suppository every 12 hours 1

Second-Line Options for Refractory Cases

• Haloperidol or droperidol for severe, refractory cases of retching 1
• Dexamethasone: 8-12 mg IV or PO for persistent symptoms 3
• Consider adding a benzodiazepine such as lorazepam (0.5-2 mg PO/IV/sublingual every 4-6 hours) for anxiety-associated retching 3

Approach Based on Suspected Etiology

For Chemotherapy-Induced Retching

• For high emetic risk chemotherapy: Use a three-drug regimen of 5-HT3 antagonist (ondansetron/granisetron/palonosetron) + dexamethasone + neurokinin-1 antagonist (aprepitant) 3
• For moderate emetic risk: Use a two-drug regimen of 5-HT3 antagonist + dexamethasone 3
• For breakthrough retching: Add an agent from a different drug class than what was used for prophylaxis 3

For Pregnancy-Related Retching

• First-line: Ginger (250 mg capsule 4 times daily) and vitamin B6 (pyridoxine, 10-25 mg every 8 hours) 3
• Second-line: H1-receptor antagonists such as doxylamine, promethazine, or dimenhydrinate 3
• For persistent symptoms: Consider doxylamine and pyridoxine combination (10 mg/10 mg or 20 mg/20 mg) 3

For Other Causes of Persistent Retching

• Assess for underlying causes requiring specific treatment (e.g., bowel obstruction, metabolic disorders) 1
• For gastroenteritis-related retching: Ondansetron has shown superior efficacy compared to other antiemetics 4
• For opioid-induced retching: Metoclopramide remains first-line 2

Supportive Care Measures

• Ensure adequate hydration with intravenous crystalloids if dehydration is present 1
• Consider nasogastric suction for gastric decompression in cases of severe retching or suspected bowel obstruction 1
• Implement dietary modifications: small frequent meals, bland foods, and avoiding spicy/fatty foods 3
• Monitor for electrolyte abnormalities and correct as needed 3, 1

Important Considerations and Cautions

• Monitor for QT prolongation with ondansetron and some dopamine antagonists, especially in patients with cardiac risk factors 1, 5
• Watch for extrapyramidal side effects with dopamine antagonists like metoclopramide and prochlorperazine 5, 6
• Consider the sedating effects of promethazine when selecting an antiemetic 7
• For prolonged retching, assess for thiamine deficiency and consider supplementation (200-300 mg daily) 1
• Avoid metoclopramide in young patients if possible, as they may be more susceptible to adverse effects 6

When to Consider Alternative Approaches

• If first-line treatments fail after 24-48 hours, reassess for underlying causes 1
• Consider adding a second agent with a different mechanism of action 2
• For persistent symptoms despite appropriate therapy, consider diagnostic testing to rule out structural causes (e.g., esophagogastroduodenoscopy or abdominal imaging) 1