Management of Acute Vomiting

Pharmacologic Management

The American Gastroenterological Association recommends ondansetron (5-HT3 antagonist) as the preferred initial agent for acute vomiting, with a sublingual tablet potentially improving absorption in actively vomiting patients 1, 2
For patients who fail ondansetron or have contraindications, the National Comprehensive Cancer Network suggests alternative or adjunctive antiemetics such as promethazine 12.5-25 mg IV/IM/rectal, prochlorperazine 10 mg IV/IM or 25 mg rectal suppository, and metoclopramide 10 mg IV/IM 1, 2, 3, 4, 5
In cases of refractory vomiting, combination therapy with a benzodiazepine (lorazepam 0.5-1 mg IV or alprazolam 0.25-0.5 mg sublingual) and haloperidol 0.5-2 mg IV may be considered, with monitoring for QT prolongation 1, 2, 3, 4

The American Gastroenterological Association recommends oral rehydration with small, frequent sips of electrolyte-rich fluids (sports drinks) for patients who can tolerate oral intake, and IV fluid therapy with normal saline or lactated Ringer's for those who cannot 1, 2, 5
IV fluids should be initiated for moderate-severe dehydration, with a 500-1000 mL bolus followed by a maintenance rate, and dextrose added if prolonged fasting or concern for hypoglycemia is present 1, 2, 5

For patients with cyclic vomiting syndrome, the American Gastroenterological Association suggests an abortive cocktail of sumatriptan (nasal spray or subcutaneous) + ondansetron + benzodiazepine, sedation with promethazine or lorazepam, and a quiet, dark environment to optimize response 1, 2, 6
IV dextrose-containing fluids are essential for patients with cyclic vomiting syndrome 1, 2

The World Journal of Emergency Surgery recommends using balanced crystalloid solutions, such as lactated Ringer's, to avoid hyperchloremic acidosis 7

The American College of Physicians, as published in the Annals of Internal Medicine, advises against giving prophylactic antiemetics in radiation exposure cases, as vomiting onset helps determine radiation dose 8