Antihistamine + vitamin B6 (NVP)
Doxylamine with pyridoxine
Brand names: Xonvea
Adult dose
Dose: 2 tablets at bedtime; up to 4 tablets/day
Route: Oral
Frequency: OD–QDS
Clinical pearls
- RCOG GTG 69 / NICE CKS Nausea & Vomiting in Pregnancy: Xonvea is the only UK-licensed first-line for NVP not improved by lifestyle measures
- Take at bedtime; warn about driving (DVLA)
- Add cyclizine/promethazine, ondansetron, metoclopramide per RCOG escalation
Contraindications
- MAOI
- Concurrent ergotamine
- Severe asthma
- Hypersensitivity
Side effects
- Drowsiness (significant)
- Anticholinergic effects
- Headache
- Dry mouth
Interactions
- MAOIs
- Other CNS depressants
- Anticholinergics
Monitoring
- Symptom control (PUQE score)
- Hydration / electrolytes
- Weight
Reference: BNF; RCOG GTG 69; NICE CKS NVP; SmPC; https://bnf.nice.org.uk/drugs/doxylamine-with-pyridoxine/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
Pathways
- Spinal Anaesthesia Hypotension Management · AAGBI; ASA
- Pre-Eclampsia / Eclampsia in ED · NICE NG133; RCOG Green-top 10A
- Suspected Ectopic Pregnancy · NICE NG126; RCOG Green-top 21
- Polycystic Ovary Syndrome (PCOS) · International PCOS Guideline 2023; NICE CKS
- Pre-eclampsia Management · NICE NG133 2019
- Ectopic Pregnancy · NICE CG154 / RCOG GTG 21