Effects of Semprex-D and diphenhydramine on learning in young adults with seasonal allergic rhinitis

Objectives: The purpose of this study was to test the hypothesis that learning ability is impaired in patients with seasonal allergic rhinitis relative to untreated individuals and to evaluate a combination compound (acrivastine 8 mg + pseudo-ephedrine 60 mg) for attenuation of the learning impairment in these patients. Background: In a previous study employing the same method it was shown that young children (10 to 12 yrs) suffering from seasonal allergic rhinitis performed significantly worse on tests of learning and using knowledge after acute treatment with a sedating antihistamine (diphenhydramine 50 mg) or placebo as compared with nontreated healthy controls. This effect was partially reversed by treatment with loratadine. Methods: Sixty-seven young adults suffering from seasonal allergic rhinitis and 28 matched controls were trained on didactic simulation for three consecutive days. Atopic subjects were treated differentially during training according to a double-blind, randomized, parallel group design with either diphenhydramine hydrochloride 50 mg, a combination compound (acrivastine 8 mg + pseudoephedrine 60 mg, A + P), or placebo, administered qd. After training, all atopic subjects were maintained on A + P treatment for 14 days at which time all groups returned for examination. Results: Mean performance at the end of training was worse for all atopic subjects combined compared with normal subjects. Subjects treated with diphenhydramine performed significantly worse than either normals (P < .001) or those treated with A + P (P < .001). At the examination, the diphenhydramine group's performance differed significantly from those of the normal (P < .001) and A + P groups (P < .001). Conclusion: The study supports our previous finding that allergy symptoms reduce learning ability which is further reduced by diphenhydramine. Atopic subjects with allergies treated with acrivastine + pseudoephedrine learned as well as normal subjects.