Montelukast, sold under the brand name Singulair among others, is a medication used in the maintenance treatment of asthma. It is generally less preferred for this use than inhaled corticosteroids. It is not useful for acute asthma attacks. Other uses include allergic rhinitis and hives of long duration. For allergic rhinitis it is a second-line treatment.[4]
Common side effects include abdominal pain, cough, and headache. Severe side effects may include allergic reactions, such as anaphylaxis and eosinophilia. Use in pregnancy appears to be safe. In 2019, concerns over neuropsychiatric side effects resulted in montelukast receiving a black box warning in the United Kingdom for behavioural changes, depression, and suicidality. Montelukast is in the leukotriene receptor antagonist family of medications. It works by blocking the action of leukotriene D4 in the lungs resulting in decreased inflammation and relaxation of smooth muscle.
Montelukast was approved for medical use in the United States in 1998. It is available as a generic medication.[5] In 2023, it was the 20th most commonly prescribed medication in the United States, with more than 25million prescriptions.