How should I manage persistent post‑viral nausea and fatigue in a patient with normal MRI and laboratory results who is experiencing dizziness and tiredness from omeprazole (Losec) and has a poor, high‑sugar diet?

Management of Persistent Post-Viral Nausea and Fatigue

Stop the omeprazole immediately—it is not indicated for post-viral gastroparesis and is causing additional symptoms without addressing the underlying problem. 1, 2

Immediate Pharmacologic Management

Start metoclopramide 10 mg orally three times daily, 30 minutes before meals, as first-line therapy for post-viral gastroparesis with nausea. 1, 2 This addresses both the nausea and promotes gastric emptying, which is the core pathophysiologic problem after viral illness. 3

If Nausea Persists After 2-4 Weeks:

• Add ondansetron 8 mg orally 2-3 times daily (available as sublingual tablets for better absorption during active nausea). 1, 2, 4 Do not replace metoclopramide—add ondansetron to target different receptor pathways for synergistic effect. 1, 4

For Severe Episodes:

• Use prochlorperazine 10 mg rectal suppositories as rescue therapy when oral route is compromised. 1, 4
• Consider haloperidol 0.5-2 mg orally every 4-6 hours if metoclopramide causes intolerable side effects. 2, 4

Critical Monitoring Parameters

Monitor for extrapyramidal symptoms (muscle stiffness, tremor, restlessness) with metoclopramide, particularly in young patients. 2, 4 While metoclopramide carries a black box warning for tardive dyskinesia, the actual risk is lower than historically estimated, and short-term use (3-6 months) for post-viral gastroparesis is generally safe. 1

Check electrolytes (potassium, magnesium) within 1-2 weeks given the duration of vomiting and risk of metabolic alkalosis. 2

Addressing the Poor Diet

The high-sugar, low-fiber diet is likely worsening gastroparesis symptoms and must be modified immediately. 1, 2

Specific Dietary Instructions:

• Eat 5-6 small meals daily instead of 3 large meals to reduce gastric distension. 1
• Eliminate high-sugar foods (sweets, candy) completely—these delay gastric emptying and worsen nausea. 1
• Avoid high-fat foods—fat significantly delays gastric emptying. 1
• Introduce easily digestible foods: white rice, bananas, applesauce, toast, boiled potatoes, well-cooked vegetables (not raw). 1
• Ensure adequate hydration: 2-3 liters of clear fluids daily, taken in small sips throughout the day. 1, 4

Expected Natural History and Prognosis

Post-viral gastroparesis has an excellent prognosis—most patients experience complete resolution within 6-12 months. 3 In a study of post-viral gastroparesis, 5 of 7 patients had complete resolution of symptoms, and the remaining 2 had considerable improvement over a mean follow-up of 32 months. 3 The autonomic dysfunction that causes delayed gastric emptying after viral illness typically recovers spontaneously. 3

When to Escalate Treatment

If symptoms persist despite metoclopramide plus ondansetron after 4-6 weeks:

• Add dexamethasone 10-20 mg intravenously for severe episodes (combination with ondansetron is superior to either agent alone). 2, 4
• Consider olanzapine 2.5-5 mg orally daily for refractory cases. 2, 4
• Refer to gastroenterology for gastric emptying study if not already performed. 1

Post-Viral Syndrome Considerations

This presentation is consistent with post-viral syndrome, which shares features with long COVID. 5 The fatigue component may represent post-exertional malaise, which requires specific management distinct from simple deconditioning. 5

For Fatigue Management:

• Implement activity pacing—not graded exercise therapy. 5 Exercise worsens symptoms in 75% of patients with post-viral fatigue and post-exertional malaise. 5
• Consider coenzyme Q10 and D-ribose supplementation, which have shown promise in post-viral fatigue syndromes. 5
• Avoid pushing through fatigue—this can worsen and prolong symptoms. 5

Critical Pitfalls to Avoid

Never use proton pump inhibitors (like omeprazole) for post-viral gastroparesis—they do not address delayed gastric emptying and add unnecessary side effects. 1, 2

Do not recommend standard exercise programs—this can significantly worsen post-viral fatigue and delay recovery. 5

Do not replace antiemetics sequentially—add medications from different drug classes to target multiple receptor pathways. 1, 4

Do not ignore the dietary component—medication alone will not succeed if the patient continues eating high-sugar, gastroparesis-triggering foods. 1, 2

Follow-Up Timeline

• Reassess symptoms in 2 weeks after starting metoclopramide and dietary modifications. 1, 2
• Check electrolytes within 1-2 weeks. 2
• If no improvement by 4-6 weeks, add ondansetron and consider gastroenterology referral. 1, 2
• Most patients improve significantly by 3-6 months with appropriate management. 3, 6