Montelukast is a leukotriene receptor antagonist (LTRA) used
for the maintenance treatment of asthma and to relieve symptoms of seasonal
allergies. It is usually administered orally as oral or chewable tablets.
Mechanism of Action:
Montelukast blocks the action of leukotriene D4 on the cysteinyl leukotriene receptor CysLT1
in the lungs and bronchial tubes by binding to it. This reduces the
bronchoconstriction otherwise caused by the leukotriene, and results in less
Because of its method of operation, it is not useful
for the treatment of acute asthma attacks. Again
because of its very specific locus of operation, it
does not interact with other allergy medications
such as theophylline.
- Following oral administration ,it is rapidly absorbed with mean bioavailability 64%.
- Food doesn’t affect absorption.
- Peak plasma concentration is achieved after 2-4 hours.
- It is metabolized and eliminated mainly via the bile.
- Mean plasma half life ranges from 2.7-5.5 hrs.
Rapidly absorbed following oral administration (bioavailability is 64%)
Toxicity Side effects:
Include headache, abdominal or stomach pain, cough, dental pain, dizziness,
fever, heartburn, skin rash, stuffy nose, weakness or unusual tiredness.
The pharmacokinetics of montelukast are similar in males and females .
The pharmacokinetic profile and the oral bioavailability of a single
10-mg oral dose of montelukast are similar in elderly and younger adults.
- Renal Insufficiency:
Since montelukast and its metabolites are not excreted in the urine, the
pharmacokinetics of montelukast were not evaluated in patients with renal
insufficiency.No dosage adjustment is recommended in these patients.
- Hepatic Insufficiency:
No dosage adjustment is required in patients with mild-to-moderate hepatic
insufficiency. The pharmacokinetics of Sedokast in patients with more severe
hepatic impairment or with hepatitis have not been evaluated .
Dosage and administration:
Adults: 10 mg to be swallowed
Children:4mg to be chewed.
One tablet once daily with or without food at bed time
Or two hours before exercise (exercise-induced asthma)