I am frequently asked about taking prochlorperazine (Buccastem® or Stemetil ®) to treat nausea due to labarynthitis, vertigo or dizziness. It is a drug I would be happy to prescribe and have used it myself as have my breastfeeding daughters. It seems a frequently asked question when the air pressure changes rapidly. Prochlorperazine may also be used for nausea

prochlorperazine and breastfeeding factsheet pdf

Brand names: Stemetil®, Buccastem®

Prochlorperazine is used to treat vertigo, labarynthitis or migraine particularly to treat nauseas caused by these conditions.

Its oral bio-availability is low due to high first-pass metabolism.  Long-term use should be avoided in breastfeeding where possible, particularly with very young babies where there is a potential risk of apnoea (breathing problems).

However short-term acute use for vertigo and labarynthitis probably poses few risks.  It is widely used for this purpose. It is licensed for use in children over 10 kg.

Compatible with use during breastfeeding if used short term. Avoid long term or where child is at risk of apnoea.

N.B This information is based on anecdote and experience as there are no research based studies on the amount passing into breastmilk.

see also https://breastfeeding-and-medication.co.uk/fact-sheet/betahistine-and-breastfeeding