Antiemetics

The prescribing of antiemetics in pregnancy can cause confusion and anxiety in the clinicians caring for patients with NVP due to concerns about the teratogenic effects. However, the absolute risk is low and the benefits outweigh the risks of leaving NVP untreated.

Oral antiemetics should be used in the first instance but may be insufficient to manage the patients symptoms. There are a variety of IM and IV antiemetics available.

Drugs from different classes can be safely combined when single agent therapy is not enough.

First line

• Doxylamine and Pyridoxine (vitamin B6) brand name Xonvea 20/20mg PO at night, increase to additional 10/10mg in morning and 10/10mg at lunchtime if required.
• Cyclizine 50mg PO, IM or IV 8 hourly
• Prochlorperazine 510mg 68 hourly PO (or 3mg buccal); 12.5mg 8 hourly IM/IV; 25mg PR daily
• Promethazine 12.525mg 48 hourly PO, IM or IV
• Chlorpromazine 1025mg 46 hourly PO, IM or IV

Second line

• Metoclopramide 510mg 8 hourly PO, IV/IM/SC
• Domperidone 10mg 8 hourly PO; 30mg 12 hourly PR
• Ondansetron 4mg 8 hourly or 8 mg 12 hourly PO; 8mg over 15 minutes 12 hourly IV; 16mg daily PR

Third line this is for the O&G service to consider commencing and is not appropriate for ED teams to start without seeking specialist input

• Hydrocortisone 100mg twice daily IV and once clinical improvement occurs, convert to prednisolone 4050 mg daily PO, with the dose gradually tapered (by 5-10mg per week) until the lowest maintenance dose that controls the symptoms is reached.