Montelukast: A Scientific and Legal Review.

Montelukast, a potent and selective cysteinyl leukotriene receptor 1 (CysLT1) antagonist, has played a transformative role in the management of asthma and allergic rhinitis. By attenuating leukotriene-driven inflammation, bronchoconstriction, and airway hyperresponsiveness, it has offered clinicians a reliable once-daily oral therapy that enhances patient adherence and symptom control. However, its clinical trajectory has become increasingly complex considering growing concerns over neuropsychiatric adverse effects, including anxiety, depression, sleep disturbances, and suicidal ideation, particularly in children and adolescents. These associations have prompted significant regulatory responses, including boxed warnings, updated prescribing information, and calls for heightened clinical vigilance. As a result, there is a renewed emphasis on thorough patient counseling, informed consent, and close monitoring of mental health symptoms during treatment. From a scientific standpoint, the precise mechanisms underlying montelukast's central nervous system (CNS) effects remain under investigation, with current research pointing toward its influence on neuroinflammatory pathways and neurotransmitter modulation. Navigating the dual narrative of montelukast-as both a highly effective respiratory therapy and a potential contributor to serious neuropsychiatric outcomes-requires a cautious, evidence-based, and patient-centered approach that integrates clinical efficacy with ethical responsibility.