Singulair
Meaning of Singulair: A controller rather than a rescue treatment, and the one common asthma tablet carrying a formal warning about mood and behavior.
Definition of Singulair
Singulair is a brand name for montelukast, a tablet taken once daily to control asthma symptoms and the symptoms of allergic rhinitis. It belongs to a class called leukotriene receptor antagonists, which block leukotrienes, inflammatory signals released by the body that tighten airway muscle, drive mucus production and swell the lining of the nose.
How does blocking leukotrienes help?
Leukotrienes are released by immune cells during an allergic reaction. They squeeze the smooth muscle wrapped around the airways, pull fluid into the lining so it swells, and increase mucus production, all of which narrow the passage air travels through. They also summon more inflammatory cells to the area, so the reaction feeds itself. Montelukast occupies the receptor these signals act on, so the message is not received. It works on one pathway only, which makes it more predictable but less powerful than treatments that suppress airway inflammation broadly.
How does it compare with an inhaler?
| Treatment | What it does | How quickly |
|---|---|---|
| Montelukast tablet | Blocks one inflammatory pathway throughout the body | Builds over days; taken every day |
| Inhaled corticosteroid | Suppresses airway inflammation broadly, acting where it is breathed in | Builds over days to weeks; taken every day |
| Short acting inhaler | Relaxes airway muscle during a flare | Minutes; used when symptoms occur |
Because the tablet is swallowed, it reaches the nose as well as the chest, which is why the same medicine treats hay fever symptoms and asthma. It is also used before exercise for people whose airways narrow with exertion.
What is the warning about?
Regulators have attached the strongest form of label warning to montelukast over reports of serious changes in mood and behavior, in adults and in children. Described effects include agitation, disturbed sleep and vivid dreams, low mood, and suicidal thoughts and behavior. Events of this kind are uncommon, but the warning changed how the drug sits among the alternatives, particularly for allergic rhinitis, where other options carry no comparable concern. Any side effect of this type is documented rather than assumed, and it can appear soon after starting or later in a course of treatment.
Also known as
Used in a sentence
Singulair was added to the patient's asthma regimen for ongoing symptom control.
Good to know
Singulair is intended for ongoing control rather than rapid relief, which separates it from a fast acting inhaler used during a sudden asthma flare, and its label carries a warning about changes in mood and behavior.