- Fexofenadine hydrochloride, 180 mg, exhibits equivalent efficacy to cetirizine, 10 mg, with less drowsiness in patients with moderate-to-severe seasonal allergic rhinitis. Hampel, F., Ratner, P., Mansfield, L., Meeves, S., Liao, Y., Georges, G. Ann. Allergy Asthma Immunol. (2003)