Much has been written about the potential of Singulair psychiatric side effects, with conflicting results. Singulair (montelukast) is a leukotriene-modifying agent approved for the treatment of asthma, exercise induced bronchospasm, perennial allergic rhinitis and seasonal allergic rhinitis. It is approved for children as young as 6 months of age depending on the condition.
In 2008/09, the FDA updated the “Warnings and Precautions” of Singulair to include agitation, aggressive behavior or hostility, anxiousness, depression, disorientation, dream abnormalities, hallucinations, insomnia, irritability, restlessness, suicidal thinking and behavior and tremor.
Since the labeling changes, there have conflicting results regarding the risks of Singulair psychiatric side effects. A recent study published in The Journal of Allergy and Clinical Immunology: In Practice, January 2021, title “Risk of Psychiatric Adverse Events Among Montelukast Users” sought to determine whether there was an association between the two. Specifically they tried to determine whether there was an increased risk of depressive disorders, self-harm and completed suicides compared to those on Singulair vs. inhaled corticosteroid use.
The study did not find any associations between Singulair use and inpatient depressive disorder or self-harm, compared with inhaled steroid use, either overall or across subgroups of age, sex or calendar time.
The data analyzed took over a 15 year period and involved 457,377 patients, exposed to either Singulair or an inhaled steroid for asthma. Psychiatric co-morbodity was common amongst patients, most psychiatric events that did occur were in patients having a past psychiatric history.
As with all new medications, patients and doctors should closely monitor for any potential side effects. There were psychiatric side effects in both treatment groups (Singulair vs. Inhaled Steroids), but the study did not show any significant increased risk compared to one another.
A limitation of the study only compared Singulair vs. inhaled steroids, it did not compare them to untreated patients.
As always speak to your doctor about any concerns you have with medications, overall the risk was very low of singulair psychiatric side effects.