Objective This review compared clinical effectiveness, cardiac safety and economics of astemizole, loratadine, cetirizine and terfenadine to provide evidence for adjustment of Essential Drug List in China. Search strategy We searched Medline, Cochrane Library, Embase and Chinese Biomedical Database. Fourteen databases for drug safety and pharmaceutical economics were additionally searched. Selection Criteria Randomized controlled trials and systematic reviews, published in English and Chinese and comparing two or more of these four antihistamines for allergic rhinitis and urticaria were included for study of effectiveness. Non-randomized clinical trials were additionally included for economic evaluation. Cardiac safety studies of antihistamines for allergic diseases of any type were included. Quality Appraisal Jadad scale was primarily applied to randomized controlled trials. Allocation concealment and intention-to-treat analysis were also appraised. The QUOROM statement was applied to systematic reviews and meta-analysis. Data extraction and analyses For the study of effectiveness, composite data were primarily extracted and analyzed by fixed effect model. Sensitivity analysis was done to explore the heterogeneity. For the study of cardiac safety, cases of adverse drug reactions and death were summarized. Difference of occurrence rate in sex and age were analyzed if possible.Electrocardiography and clinical symptoms were summarized. Results No studies on economic evaluation were identified. 27 and 6 randomized controlled trials, including 3 227 participants, for allergic rhinitis and urticaria were identified. Cetirizine was superior to loratadine (n=709) in symptom score and onset of action, superior to terfenadine (n=645) in Quality of Life and superior to astemizole (n=498) in patient satisfaction and onset of action. 73 h-ADR cases were identified in astemizole, 27 cases in terfenadine, 1 case in loratadine and none in cetirizine. No deaths were identified. Combination of terfenadine plus grapefruit juice (n=l8), itraconazole (n=6), nefazodone (n=67), and loratadine administration concomitant with cemitidine (n=30) significantly prolonged QTc interval. Conclusions Cetirizine was superior to other three antihistamines in terms of clinical effectiveness and drug safety. Astemizole and terfenadine could cause significantly more cardiac-related adverse reactions than cetirizine and loratadine.
