Step 1
- ›Cyclizine 50 mg PO/IV/IM TDS
- ›OR promethazine 25 mg PO/IM TDS
Step 2
- ›Prochlorperazine 5–10 mg PO TDS or 12.5 mg IM/IV TDS
- ›Metoclopramide 10 mg TDS (max 5 days — EPS risk)
Step 3
- ›Ondansetron 4–8 mg TDS (small ↑ cleft palate risk in T1 — counsel)
- ›IV fluids: Hartmann's or 0.9% saline + K⁺ replacement
Step 4 (refractory)
- ›Hydrocortisone 100 mg IV BD, then prednisolone 40 mg PO daily wean
- ›Always give IV thiamine BEFORE any dextrose
Common mistakes
- •Giving glucose without thiamine → Wernicke's encephalopathy.
- •Forgetting VTE prophylaxis in admitted HG patients.
- •Missing hyponatraemia/hypokalaemia — check U&E daily.