Neuropsychiatric diagnoses after montelukast initiation in paediatric patients with asthma

Background The evidence base on montelukast-associated adverse outcomes is inconclusive in children and young persons (CYP) with asthma. We aimed to investigate 1-year incidence of neuropsychiatric diagnoses after initiation of montelukast as an adjunct therapy to inhaled corticosteroids (ICSs) in CYP aged 3-17 years with asthma.Methods This propensity score matched cohort study was conducted using electronic health records between 2015 and 2019 in the TriNetX Analytics Network patient repository in the USA. Neuropsychiatric diagnoses were identified using the International Statistical Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes. We estimated risk ratios (RRs), absolute risk increase (ARI) and number needed to harm (NNH) with 95% CIs.Findings The mean age (SD) at index prescription in the 107 384 CYP with asthma was 8.7 (4.0) years (93 461 (87%) mild to moderate asthma; 62 301 (58%) male; 53 485 (50%) white; 33 107 (31%) black/African American). Montelukast was associated with excess incidence of any neuropsychiatric outcome (71 per 1000 persons with montelukast and 54 per 1000 persons with no montelukast; RR 1.32 (95% CI 1.25 to 1.39); ARI per 100 persons, 1.71 (95% CI 1.44 to 1.98); 1-year NNH, 58 patients (95% CI 51 to 69)). The highest excess risk in the montelukast group was for sleep disorders (RR 1.63 (95% CI 1.50 to 1.77); ARI per 100 persons 1.17 (95% CI 1.00 to 1.33); NNH, 85 patients (95% CI 75 to 100)). Montelukast use was also associated with excess incidence of anxiety disorders (RR 1.16 (95% CI 1.08 to 1.24)) and mood disorders (RR 1.16 (95% CI 1.05 to 1.29)).Conclusions In CYP with asthma who were treated with ICSs, adjunct treatment with montelukast was associated with a higher incidence of neuropsychiatric outcomes compared with those who were not exposed to montelukast.