Polaramine (dexchlorpheniramine maleate) how harmful?

Safe enough. Polaramine (dexchlorpheniramine maleate) (dexchlorphemiramine) is an old-fashioned, reliable antihistamine. It may make you more drowsy than modern antihistamines, and tends to dry up secretions which may help a runny nose or annoy you by making your eyes and mouth dry.