A greater number of cumulative days of montelukast use did not increase the risk of ADHD in these patients.
Investigators from Kaohsiung Chang Gung Memorial Hospital, Taiwan, conducted a nationwide population-based cohort study to evaluate whether montelukast use among asthmatic children increases risk for ADHD.
To do this, they used data from the Taiwan nationwide health insurance research database (NHIRD), a longitudinal database of one million randomly selected subjects. Thus, they included patients ≤12 years old with new-onset asthma diagnosed between 1997-2013. Patients were followed up until 2013.
Excluded from the study were those with a diagnosis of ADHD prior to baseline period or who had previously used montelukast.
“If patients develop ADHD within six months after taking montelukast, patients are considered to have already had symptoms of ADHD prior to using montelukast,” they clarified.
Overall, they enrolled a total of 54,487 with ≥1 claim of inpatient admissions or ≥3 claims of an ambulatory visit. In a 1:1 ratio, they matched montelukast users and controls by age, gender, residence, comorbidities including allergic rhinitis and atopic dermatitis, admission or emergency department visits to asthma attach, and index date of starting montelukast.
The investigators then used a multivariate Cox regression analysis to evaluate the association between montelukast use and ADHD risk.
The primary outcome sought by the investigators was the occurrence of ADHD (identified using ICD-9-CM codes).
Thus, they found a similar level of ADHD risk between the montelukast (4.94%) and control (4.76%) groups (adjusted HR, 1.04; 95% CI, 0.93-1.17).
“In children treated with montelukast, a high number of cumulative days (>90 days) of montelukast use did not increase the risk of ADHD,” the investigators wrote.
They also noted that the montelukast cohort exhibited higher rates of autistic spectrum disorder and tic disorder (both P<.05).
Additionally, there was no observed association between ADHD and allergic rhinitis through univariate analysis (P = .2737). However, according to multivariate analyses, allergic rhinitis was associated with a lower rate of ADHD (HR, 0.81, 95% CI%, 0.68-0.98).
Two limitations acknowledged by the investigators were the overreliance on diagnostic codes as well as the lack of consideration of the physician department responsible for diagnosis.
“In this population-based cohort study of NHIRD data, montelukast was not associated with a subsequent risk of ADHD in children and adolescents with asthma,” they concluded. “Our data can serve as a reference for parents, educating them that they do not need to refuse montelukast for their asthmatic children due to a fear of ADHD.”
They underscored the safety of montelukast therapy, yet acknowledged a need to further validate results in prospective studies.
The study, “Montelukast does not increase the risk of attention-deficit/hyperactivity disorder in pediatric asthma patients: A nationwide population-based matched cohort study,” was published online in ScienceDirect.