Drug name	FDA pregnancy risk classification	Drug class	Crosses placenta?	Use in pregnancy
Chlorpheniramine (Chlor-Trimeton)	B	Antihistamine	Not known	Antihistamine of choice
Pseudoephedrine hydrochloride (Novafed)	B	Sympathomimetic decongestant	Not known	Oral decongestant of choice10, possible association with gastroschisis9
Guaifenesin (Humibid L.A.)	C	Expectorant	Not known	May be unsafe in first trimester*
Dextromethorphan hydrobromide (Benylin DM)	C	Non-narcotic antitussive	Not known	Appears to be safe in pregnancy
Diphenhydramine (Benadryl)	B	Antihistamine/antiemetic	Yes	Possible oxytocin-like effects at high dosages
Clemastine fumarate (Tavist)	B	Antihistamine	Not known	Unknown safety profile