montelukast

Action and Spectrum

Many different types of cells, including mast cells and eosinophils, emit eicosanoids called cysteinel leukotrienes (Cysl). CysLT binds to corresponding CysLT receptors, such as CysLT type-1 receptors, which are found on several pro-inflammatory cells, including eosinophils and some myeloid stem cells, as well as respiratory airway smooth muscle cells and airway macrophages. 

The actions of CysLT that promote asthma include vascular permeability, occluding mucous secretion, eosinophil recruitment, and airway bronchoconstriction. 

CysLTs contribute to the development of symptoms such as a clogged nose and airway in allergic rhinitis and are released by the nasal mucosa in response to allergen exposure during both early and late phase reactions. 

Drug Interaction

Adverse Reaction

Frequency defined:   

1%-10%  

Atopic dermatitis 

Eczema (2%) 

Skin rash 

Urticaria 

Abdominal pain 

Diarrhea 

Dyspepsia 

Gastroenteritis 

Nausea  

Toothache  

Pyuria  

Increased serum alanine aminotransferase  

Influenza  

Dizziness 

Headache  

Asthenia 

Conjunctivitis   

Postmarketing: 

Edema 

Erythema multiforme 

Pancreatitis 

Vomiting 

Black Box Warning

There have been reports of severe neuropsychiatric episodes among montelukast users, including suicidal thoughts or behaviours.
Montelukast should only be used for allergic rhinitis in patients who have not responded well to or are intolerant of other treatments.
Inform every patient of the possibility of neuropsychiatric problems before writing a prescription. 

If you experience any changes in behavior, new neuropsychiatric symptoms, suicidal thoughts, or conduct, stop using it right away and get in touch with a healthcare provider. 

Contraindication / Caution

Contraindication: 

Hypersensitivity 

Caution: 

Neuropsychiatric events  

Systemic eosinophilia  

Phenylketonuria 

Status asthmaticus and other acute asthma attacks should not be treated with this medication. 

Pregnancy / Lactation

Pregnancy consideration: As per published data montelukast does not show the risk of birth defects. 

Lactation: Montelukast may be excreted in a breast milk.  

Pregnancy category: 

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester. 
• Category B: There is no evidence of risk to the fetus found in animal reproduction studies and there are not enough studies on pregnant women. 
• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for an effect in humans, care must be taken for potential risks in pregnant women 
• Category D: There is adequate data available with sufficient evidence of human fetal risk from various platforms, but despite potential risks may be used only in emergency cases for potential benefits. 
• Category X: Drugs listed in this category outweigh risks over benefits These category drugs should be prohibited for pregnant women. 
• Category N: There is no data available for the drug under this category. 

Pharmacology

It also blocks binding of leukotriene D4 to its receptor. The leukotriene receptor type-1 is demonstrated to have a high affinity and specificity for the leukotriene receptor antagonist montelukast. 

During double-blind treatment periods, montelukast was lower mean peripheral blood eosinophils by 13% to 15% from baseline as compared to placebo in clinical trials involving adults and juvenile asthmatic patients aged 6 to 14. 

When compared to a placebo, montelukast also resulted in a median 13% decrease in peripheral blood eosinophil counts in individuals with seasonal allergic rhinitis who were 15 years of age or older. 

Adminstartion

It should be taken with or without food for oral administration. 

Patients suffering from both asthma and allergic rhinitis should take only one dose in the evening. 

In Asthma or EIB cases:  

Dose should be administered in the evening only. 

For Oral granules: 

Mix with a spoonful of cold or room temperature soft foods, dissolve in 1 teaspoon (5 mL) of cold or room temperature breast milk or infant formula or administer directly into the mouth. 

Before using the packet, do not open it.
It must be opened and the entire dose given within 15 minutes, whether it has been mixed with food, breast milk, or infant formula. 

To provide oral granules, they should only be dissolved in breast milk or infant formula. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: montelukast 

Why do we use montelukast?  

Montelukast is used in the prevention and long-term management of asthma in adults and children aged 12 months and older. 

It is also used in the prevention of exercise-induced bronchoconstriction (EIB). 

It is used to relief symptoms of seasonal allergic rhinitis and perennial allergic rhinitis.