What is the appropriate treatment for a patient with a one‑week history of a persistent soapy odor and associated nausea and vomiting, with normal basic metabolic panel, complete blood count, thyroid panel, and liver enzymes?

Management of Persistent Soapy Smell with Nausea and Vomiting

This patient requires immediate treatment with scheduled metoclopramide 10 mg every 6 hours (not PRN) for up to 5 days, while simultaneously investigating for underlying neurological causes given the unusual olfactory hallucination. 1, 2

Critical First Steps

Rule Out Serious Underlying Causes

Your laboratory workup appropriately excludes most metabolic emergencies, but the complaint of a persistent "soapy smell" (phantosmia/olfactory hallucination) lasting one week is a red flag that demands neurological evaluation. 3

• Obtain urgent brain imaging (MRI preferred, CT if MRI unavailable) to exclude:

  • Brain metastases or primary CNS tumor 4, 1
  • Stroke or other intracranial pathology 5, 6
  • Temporal lobe lesions (which commonly cause olfactory hallucinations) 7

• Check for additional neurological symptoms: headache severity, visual changes, focal weakness, seizure activity 5, 6

• Verify medication list for drugs causing olfactory disturbances or nausea (opioids, antibiotics, chemotherapy agents) 3, 5

Address Metabolic Concerns

While your basic labs are reassuring, consider:

• Calcium level is normal (9.4 mg/dL), ruling out hypercalcemia 1, 3
• Electrolytes are within normal limits 1
• Thyroid function is normal, excluding thyroid storm 4
• The slightly elevated RDW (15.6%) and platelets (453) are nonspecific but warrant monitoring 5

Immediate Pharmacologic Management

First-Line Treatment: Scheduled Dopamine Antagonist

Start metoclopramide 10 mg orally every 6 hours on a scheduled basis (not PRN) for persistent symptoms. 1, 3, 2

• Maximum duration: 5 days only to minimize risk of tardive dyskinesia and extrapyramidal effects 2, 8
• This provides both central antiemetic effects and peripheral prokinetic action 2, 8
• Do NOT use PRN dosing—scheduled administration is essential for persistent symptoms 2
• Contraindication check: Ensure no bowel obstruction (your normal labs and lack of abdominal distention suggest this is not present) 1, 2

If Vomiting Prevents Oral Intake

Given active vomiting, the oral route may not be feasible initially. 4, 1

• Alternative: Metoclopramide 10 mg IV/IM every 6 hours 8
• Consider ondansetron 8 mg sublingual every 8 hours as it bypasses the need for swallowing 1
• Prochlorperazine 25 mg rectal suppository every 12 hours is another option 1

Second-Line: Add 5-HT3 Antagonist if No Response in 24-48 Hours

If nausea/vomiting persists despite scheduled metoclopramide: 1, 3

• Add ondansetron 8 mg orally/sublingual every 8 hours (targets different receptor pathway) 1, 3
• This combination addresses both dopaminergic and serotonergic pathways 4, 1

Supportive Care

• Ensure adequate hydration: Start IV normal saline if unable to tolerate oral fluids 4, 1
• Correct any electrolyte abnormalities (yours are currently normal but recheck if vomiting continues) 4, 1
• Consider proton pump inhibitor (omeprazole 20 mg daily) if gastritis/reflux suspected 1, 3

Critical Pitfalls to Avoid

1. Do not continue metoclopramide beyond 5 days without reassessing—risk of irreversible tardive dyskinesia increases with prolonged use 2, 8

2. Do not use antiemetics if bowel obstruction develops—metoclopramide can worsen obstruction 1, 2

3. Do not dismiss the olfactory hallucination—this is NOT a typical presentation of gastroenteritis or simple nausea and mandates CNS imaging 5, 6

4. Do not use PRN-only dosing—around-the-clock scheduled dosing is required for persistent symptoms 4, 1, 2

5. Monitor for extrapyramidal side effects with metoclopramide (akathisia, dystonia, parkinsonism) 1, 8

If Symptoms Persist After 5 Days

Should symptoms continue beyond the 5-day metoclopramide course: 1, 3

• Add olanzapine 2.5-5 mg daily (highly effective for refractory nausea) 4, 3
• Consider lorazepam 0.5-1 mg every 6 hours if anxiety component present 4, 3
• Reassess for gastroparesis with gastric emptying study if chronic symptoms develop 4
• Consider neurology consultation given the persistent olfactory hallucination 5, 6

Follow-Up Plan

• Recheck basic metabolic panel in 2-3 days if vomiting continues (assess for dehydration, electrolyte shifts) 1
• Obtain brain imaging within 24-48 hours given the unusual olfactory symptom 5, 6
• Reassess in 5 days maximum to determine if metoclopramide should be discontinued and alternative agents started 2
• Document response to therapy and any adverse effects 1

The combination of phantosmia (soapy smell) with nausea/vomiting is atypical for simple gastroenteritis and warrants aggressive investigation for CNS pathology while simultaneously treating symptoms. 5, 6, 7