Assessment of the expectancy, seriousness and severity of adverse drug reactions reported for chronic obstructive pulmonary disease therapy

INTRODUCTION Adverse drug reactions can cause increased morbidity and mortality, and therefore information needs to be studied systematically. Little is known about the adverse drug reactions for chronic obstructive pulmonary disease therapy. The goal of this study is to assess the expectedness, seriousness and severity of adverse drug reactions during chronic obstructive pulmonary disease therapy based on their reporting in the national pharmacovigilance system. METHODS This was a prospective, observational, 1-year, real-life study about the pharmacotherapy of a sample of 390 chronic obstructive pulmonary disease patients. Prescribed medicines were systematized and national pharmacovigilance databases were searched for reported adverse drug reactions. The expectedness was evaluated through the review of the summary of product characteristics, the seriousness was evaluated by the clinicians based on the life threatening nature of the adverse drug reactions, and the severity was evaluated through Hartwig's Severity Assessment Scale. Descriptive statistics of the reported adverse drug reactions was performed and the relative risk of developing an adverse drug reaction with all international non-proprietary names included in the analysis was calculated. RESULTS Results confirm that the chronic obstructive pulmonary disease is a disease with high appearance of adverse drug reactions, and causes many additional costs to the healthcare system. Unexpected and severe adverse drug reactions are frequent. A total of 4.8% of adverse drug reactions were evaluated as life threatening. Majority of adverse drug reactions are classified in Levels 1 (32.6%), 2 (26.4%) and 3 (19%) according to Hartwig's Severity Assessment Scale. Approximately 22% of reported adverse drug reactions affect people's everyday life to a greater extent and require additional therapy which might further increase the risk. The relative risk of developing an adverse drug reaction was highest for novphyllin (relative risk = 0.65), followed by aclidinium bromide (relative risk = 0.09). Both indacaterol and salbutamol are with a relative risk of 0.07. CONCLUSION In conclusion, the medicines for chronic obstructive pulmonary disease cause many serious adverse drug reactions, most of them were unexpected, lacking in the short product characteristics. Appropriate reporting of adverse drug reactions is necessary to decrease the risk of patients and healthcare system.