Sedation with "non-sedating'' antihistamines: four prescription-event monitoring studies in general practice

Objectives To investigate the frequency with which sedation was reported in post-marketing surveillance studies of four second generation antihistamin es: loratadine, cetirizine, fexofenadine, and acrivastine. Design Prescription-event monitoring studies. Setting Prescriptions were obtained for each cohort in the immediate post-m arketing period. Subjects Event data were obtained for a total of 43 363 patients. Main outcome measure Reporting of sedation or drowsiness. Results The adds ratios (adjusted for age and sex) for the incidence of sed ation were 0.63 (95% confidence interval 0.36 to 1.11; P = 0.1) for fexofen adine; 2.79 (1.69 to 4.58; p < 0.0001) for acrivastine, and 3.53 (2.07 to 5 .42; P < 0.0001) for cetirizine compared with loratadine. No increased risk of accident or injury it as evident with any of the four drugs. Conclusions Although the risk of sedation was low with all four drugs, fexo fenadine and loratadine may be more appropriate for people working in safet y critical jobs.