risk of insomnia, post-marketing surveillance showed that the drugs are associated with a possible increase in suicidal behavior and other side effects such as agitation, aggression, anxiousness, dream abnormalities and hallucinations, depression, irritability, restlessness, and tremor. In September 2019, the Pediatric Advisory Committee and the Drug Safety and Risk Management Advisory Committee met to discuss a pediatric-focused safety review of neuropsychiatric events with montelukast. In March 2020, the FDA required a boxed warning for montelukast to strengthen an existing warning about the risk of neuropsychiatric events associated with the drug in the wake of an increase in case reporting of neuropsychiatric events around the time of the initial communications about the concern from FDA in 2008. The boxed warning advises health care providers to avoid prescribing montelukast for people with mild symptoms, particularly those with allergic rhinitis because there are many other effective, less-concerned allergy medicines that are also indicated for the mild cases. In the FDA's self-conducted data analysis in comparison to their received case reports which were dependent on people's self-claims, the propensity of developing neuropsychiatric disorders after montelukast use does not outpace that of inhaled corticosteroids; and there were no statistically significant risks of new-onset neuropsychiatric disorders among males, females, patients 12 years and older, patients with a psychiatric history, or after the 2008 FDA communication and prescribing information changes that first publicized the concern. In addition, FDA's self-conducted data analysis also summarized their own findings, saying "exposure to montelukast was significantly associated with a decreased risk of treated outpatient depressive disorder and the decreased risks were seen among patients with a history of a psychiatric disorder, in patients 12 to 17 years as well as 18 years and older, and in both females and males." "Treated outpatient depressive disorder" refers to patients' actions of making an appointment with psychiatrists to contend with their depressions. Drug interactions Montelukast is an inhibitor of the drug metabolizing enzyme CYP2C8, part of the cytochrome P450 system. Therefore, it is theoretically possible that the combination of montelukast with a CYP2C8 substrate (e.g. amodiaquine, an anti-malarial drug) could increase the plasma concentrations of the substrate. However, clinical studies have shown minimal interactions between montelukast and other CYP2C8 substrate drugs, which is most likely due to the high plasma protein binding exhibited by montelukast. Pharmacology Montelukast is in the leukotriene receptor antagonist family of medications. It works by blocking the action of leukotriene