Introduction: Leukotriene-modifying agents (LTMAs) including montelukast, zafirlukast, and zileuton are approved by the US Food and Drug Administration (FDA) for the treatment of asthma and allergic rhinitis. Various neuropsychiatric events (NEs) have been reported; however, the evidence of the association is conflicting. This systematic review investigates the association between NEs and LTMAs by assessing the relevant published literature.
Methods: PubMed, EMBASE, MEDLINE, and Cochrane Library were searched using keywords. Studies designed to investigate the association were eligible for inclusion without restriction to any study design or language. The primary outcome was defined as suicidal conditions, while secondary outcomes included all other NEs.
Results: Thirty-three studies were included for a narrative review. Four observational studies did not find a significant association, while ten pharmacovigilance studies using different global databases detected the signals. Notably, some studies suggest that the FDA warning issued in 2008 might have influenced the reporting rate of NEs as a result of increased awareness.
Limitations: The risk of NEs was not quantified, because of the lack of randomized controlled trials and observational studies investigating the association.
Conclusion: Many pharmacovigilance studies have been conducted to determine the association between NEs and LTMAs, but there is limited evidence from observational studies. High-quality epidemiological studies should be conducted to evaluate the association and quantify the risk, not only in children, but also in adults.