Antihistamines, pregnancy

For some of the antihistamines frequently used in dermatology/allergology, there is good data on their use in pregnancy.
The non-sedating antihistamines loratadine and cetirizine have been best investigated with > 5000 and > 1000 prospectively observed pregnancies respectively. For both drugs there is no evidence of embryo or fetotoxic effects.

Newer antihistamines such as desloratadine and levocetirizine as well as fexofenadine have been less well investigated with regard to their use in pregnancy.
For ebastine and rupatadineonly animal experimental data are available.

Sedative antihistamines(clemastine, hydroxyzine and dimetindene) have not shown a hematogenic risk so far. The greatest experience is with clemastine. It is recommended to use sedative antihistamines only from the second trimester onwards.

1. Grunewald S et al.(2017) Dermatological topical and systemic therapy during pregnancy. Dermatologist 68:127-135.