Loratadine versus cetirizine: Assessment of somnolence and motivation during the workday

Objective: This parallel-group, double-blind study compared the somnolence and motivation profiles of 2 second-generation antihistamines, loratadine a nd cetirizine, in patients with allergic rhinitis. Background Second-generation antihistamines were developed to provide sympt omatic relief from allergic disorders without the unwanted side effects of first-generation antihistamines, including somnolence. Recent research has indicated that not ail second-generation antihistamines are comparable with respect to somnolence and other cognitive processes. Methods: Patients aged greater than or equal to 12 years and actively exhib iting Symptoms of allergic rhinitis were randomized to 2 treatment groups t o receive 10 mg loratadine or 10 mg cetirizine daily at 8:00 AM for 1 week. After patients took the medication, their somnolence and degree of motivat ion to perform activities were recorded in an electronic diary using a visu al analog scale 4 times during the workday (8:00 AM, 10:00 AM, noon, and 3: 00 PM). Results: Sixty patients (31 men, 29 women) were randomized to treatment. So mnolence scores were similar for both groups at baseline and at the time of dosing (8:00 AM). However, there was a statistically significant differenc e in somnolence scores between the loratadine and cetirizine groups at 10:0 0 AM (P = 0.008), noon (P = 0.001), and 3:00 PM (P < 0.001), with the cetir izine group showing a greater degree of somnolence. The scores on motivatio n to perform activities were similar for both groups at the baseline and 8: 00 AM measurements. In parallel with the somnolence scores, there were stat istically significant differences in motivation scores between the loratadi ne and cetirizine groups at 10:00 AM (P = 0.014), noon (P = 0.001), and 3:0 0 PM (P < 0.001), indicating that patients taking loratadine were relativel y more motivated during the workday. Conclusion The results of this study demonstrate that in patients aged grea ter than or equal to 12 years who had allergic rhinitis, cetirizine use pro moted somnolence and decreased motivation to perform activities during the workday compared with loratadine.