Safety Data on Antiemetics
Concerns about the safety of antiemetics has resulted in many patients having their symptoms inadequately treated out of a concern for medication teratogenicity.
The current guidance is that the absolute risk of causing conditions such as cleft palate are incredibly low.
Antihistamines, Phenothiazines and Pyridoxine-Doxylamine all have good safety data.
Ondansetron has a very small increase in the absolute risk of orofacial clefting when used in the first trimester (from 11 per 10,000 births background rate, to 14 per 10,000 births).7
Metoclopramide is safe and can be used as a standalone agent or in combination with other agents. There is a small risk of extrapyramidal side effects and oculogyric crisis, so it should be utilised as a 2nd line agent.