Characterization of adverse reactions to two antihistamine drugs: A descriptive analysis from WHO-VigiAccess.

INTRODUCTION: Antihistamines like azelastine and levocabastine are key in treating allergies, including allergic rhinitis, conjunctivitis, and urticaria. This study analyzed adverse drug reactions linked to these drugs using data from the WHO VigiAccess database, comparing their adverse drug reaction profiles to help physicians choose lower-risk options for personalized treatment. METHODS: A retrospective descriptive analysis was used, with data from WHO-VigiAccess on azelastine and levocabastine. Included were global patient demographics (age, gender, location) and details on illness systems/symptoms from direct and annual adverse drug reaction reports. Adverse drug reaction percentages for each drug were calculated for comparison. RESULTS: Over the study period, 11,592 adverse events related to both drugs were reported. Both had high rates of General disorders and administration site conditions. Azelastine showed more Nervous system disorders. Levocabastine had higher rates of endocrine disorders, injury/poisoning/procedural complications, and Nervous system disorders. The top five adverse events were: General disorders (4463, 36.7%), Nervous system (3475, 28.6%), Gastrointestinal (1558, 12.8%), Respiratory (1515, 12.5%), and Injury/poisoning (871, 7.2%). For SOC-reported ADRs, > 10% incidence occurred in 2 azelastine cases and 4 levocabastine cases. CONCLUSION: Clinicians should note antihistamine ADRs. This study identifies common and specific reactions reported to the WHO, aiming to guide safer, more judicious use of these drugs.