Products
Montelukast is commercially available as film-coated tablets and as granules and chewable tablets for children (Singulair, generic). It has been approved in many countries since 1998.
Structure and properties
Montelukast (C35H36ClNO3S, Mr = 586.18 g/mol) is a chloroquinoline derivative. It is present in drugs as montelukast sodium, a white crystalline powder that is readily soluble in water.
Effects
Montelukast (ATC R03DC03) has antiasthmatic, anti-inflammatory, bronchodilator, and antiallergic properties. It binds with high affinity and selectivity to the CysLT1 receptor, thereby inhibiting the effects of the cysteinyl leukotrienes LTC4, LTD4, and LTE4. These are potent inflammatory mediators that cause bronchoconstriction, increased vascular permeability, mucus secretion, and inflammatory cell accumulation, among other effects. Montelukast, unlike other asthma medications, can be administered perorally and does not need to be inhaled. It is particularly common in pediatrics and is approved for children two years of age and older.
Indications
For the treatment of chronic bronchial asthma and for the relief of symptoms of allergic rhinitis (e.g., hay fever). Also used in some countries to prevent exercise-induced asthma.
Dosage
According to the drug label. For asthma therapy, the drug is taken once daily before bedtime, regardless of meals. For the treatment of allergic rhinitis, it may also be administered in the morning. The drug is taken continuously and is not suitable for the treatment of an acute asthma attack!
Contraindications
- Hypersensitivity
For complete precautions, see the drug label.
Interactions
Montelukast is metabolized by CYP3A4, CYP2C8, and CYP2C9 and is an inhibitor of CYP2C8. Corresponding drug-drug interactions are possible and have been observed, for example, with enzyme inducers.
Adverse effects
The most common potential adverse effects include diarrhea, nausea, vomiting, rash, upper respiratory tract infection, and fever. Neuropsychiatric disorders such as abnormal dreaming, hallucinations, irritability, depression, and suicidal ideation have been reported. The physician should be contacted if such side effects occur.
