What is the treatment for dizziness, nausea, and vomiting?

Treatment of Dizziness, Nausea, and Vomiting

For acute nausea and vomiting in adults, start with ondansetron (5-HT3 antagonist) as first-line therapy due to its superior safety profile, or use metoclopramide or prochlorperazine (dopamine antagonists) when gastroparesis or gastric stasis is suspected. 1, 2, 3

Initial Assessment Priorities

Before initiating treatment, rapidly identify life-threatening causes and assess hydration status:

• Red flag symptoms requiring immediate evaluation: bilious or bloody vomiting, severe abdominal pain suggesting obstruction, altered mental status, signs of increased intracranial pressure (headache with positional changes, focal neurological deficits), severe dehydration, or metabolic abnormalities 1, 4
• Medication review is mandatory: many drugs cause nausea/vomiting as adverse effects, and this is among the most common reversible causes 5, 4
• Assess for underlying causes: gastroparesis, bowel obstruction, severe constipation, gastroesophageal reflux, metabolic abnormalities, or pregnancy 1, 4

Stepwise Pharmacologic Treatment Algorithm

First-Line Antiemetic Selection

Choose based on clinical context:

• Ondansetron (5-HT3 antagonist): 8 mg orally or IV, repeat every 8 hours as needed 6, 3

  • Most appropriate when sedation must be avoided
  • No risk of extrapyramidal side effects or akathisia
  • FDA-approved for chemotherapy-induced, radiation-induced, and postoperative nausea/vomiting 6
  • Effective in 66% of patients with highly emetogenic stimuli 6

• Metoclopramide (dopamine antagonist): 10 mg orally three times daily before meals 1, 2

  • Preferred when delayed gastric emptying or gastroparesis is suspected
  • Prokinetic effects enhance gastric motility
  • Black box warning: Risk of tardive dyskinesia, especially with prolonged use >12 weeks 1
  • Monitor for extrapyramidal symptoms (akathisia, dystonia) within 48 hours 7, 3

• Prochlorperazine (dopamine antagonist): Alternative dopamine antagonist with similar efficacy to metoclopramide 7, 1

  • Also carries risk of akathisia requiring monitoring 3
  • Can reduce infusion rate to minimize akathisia; treat with diphenhydramine if occurs 3

Second-Line: Add Agents from Different Drug Classes

If vomiting persists after 48 hours (inpatient) or 1 month (outpatient), add one or more agents targeting different receptors: 1

• Antihistamines (H1 antagonists): diphenhydramine, meclizine - particularly effective for vestibular causes 2
• Anticholinergics: scopolamine - reduces nausea/vomiting without causing dizziness, drowsiness, or blurred vision 7
• Corticosteroids: dexamethasone - add to existing regimen for refractory symptoms 7, 1, 2
• Haloperidol: effective dopamine antagonist for breakthrough symptoms 7, 1

Third-Line: Refractory Symptoms

For multiply refractory cases: 1, 2

• Olanzapine: superior efficacy in some studies for breakthrough vomiting 1
• Continuous IV or subcutaneous infusion of antiemetics 1
• Combination therapy targeting multiple receptor sites simultaneously 2
• Cannabinoids: consider as adjunct 2

Special Clinical Contexts

Migraine-Associated Symptoms

• Prokinetic antiemetics are specifically recommended: domperidone or metoclopramide as adjunct oral medications 7
• Address the underlying migraine with appropriate acute therapy (NSAIDs, triptans) 7

Postoperative Nausea/Vomiting

• Prophylaxis with 5-HT3 antagonists plus dexamethasone is more effective than single agents 7
• Ondansetron 16 mg administered 1 hour before anesthesia induction for prevention 6
• Multiple agents targeting different mechanisms provide synergistic benefit 7

Anxiety-Related Nausea

• Add benzodiazepines (lorazepam) to antiemetic regimen 1
• Avoid long-term benzodiazepine use due to dependence risk 1

Gastroesophageal Reflux/Gastritis

• Proton pump inhibitors or H2 receptor antagonists should be initiated 1

Critical Prescribing Considerations and Pitfalls

Avoid these common errors:

• Never use antiemetics in suspected mechanical bowel obstruction - may worsen condition and delay surgical intervention 1
• Do not switch within the same drug class for breakthrough symptoms - instead add agents from different classes 1, 2
• Reduce corticosteroid doses by 50-75% when co-administering with aprepitant (NK1 antagonist) due to CYP3A4 interactions 2
• Promethazine has potential for vascular damage with IV administration and causes excessive sedation 3
• Monitor for QT prolongation with ondansetron, especially in patients with cardiac risk factors 6
• Limit metoclopramide duration to minimize tardive dyskinesia risk 1
• Droperidol is reserved for refractory cases only due to FDA black box warning for QT prolongation 3

Dosage Adjustments

Hepatic impairment: Do not exceed 8 mg total daily dose of ondansetron in severe hepatic impairment (Child-Pugh ≥10) 6

Elderly patients: Start with lower doses and monitor closely for extrapyramidal side effects with dopamine antagonists 2