Brand Names for Doxylamine-Pyridoxine Combination
The doxylamine-pyridoxine combination is available under several brand names, with Xonvea® being the primary formulation referenced in UK guidelines, while Diclegis® and Diclectin® are the North American equivalents. 1, 2
Available Brand Formulations
United Kingdom and Europe
- Xonvea® - This is the delayed-release tablet formulation specifically mentioned in the 2024 BJOG guidelines as a first-line antiemetic for nausea and vomiting of pregnancy 1
- Cariban® - A modified-release capsule formulation containing doxylamine 10 mg/pyridoxine 10 mg, available in European markets 3, 4
North America
- Diclegis® - FDA-approved delayed-release tablet formulation (approved April 2013 in the United States) containing doxylamine succinate 10 mg and pyridoxine hydrochloride 10 mg 2, 5, 6
- Diclectin® - The Canadian market equivalent, available since 1979 5, 6
Key Formulation Details
All branded products contain the same active ingredient doses: 10 mg doxylamine succinate and 10 mg pyridoxine hydrochloride per unit 2. The FDA labeling describes these as delayed-release tablets designed for oral administration, with dosing starting at two tablets at bedtime and potentially increasing to a maximum of four tablets daily (one morning, one mid-afternoon, two at bedtime) 2.
Important Distinction Between Formulations
Research demonstrates that Xonvea® tablets exhibit gastro-resistant properties with rapid release in intestinal pH conditions (20-30 minutes), while Cariban® capsules show prolonged-release characteristics with gradual dissolution over 4-5 hours 4. This difference in release profiles may impact onset of action, with the tablet formulation potentially providing faster symptom relief 4.
All these branded formulations have extensive safety data supporting their use as first-line therapy for nausea and vomiting of pregnancy, with FDA Pregnancy Category A status based on studies of over 200,000 exposed pregnancies showing no increased risk of congenital malformations 5, 6.