Montelukast sodium, the active ingredient in SINGULAIR (
Manufacturer: Merck ) , is a selective and orally active leukotriene receptor antagonist that inhibits the cysteinyl leukotriene CysLT 1 receptor.
Montelukast sodium is described chemically as [ R -( E )]-1-[[[1-[3-[2-(7-chloro-2-quinolinyl)ethenyl]phenyl]-3-[2-(1-hydroxy-1-methylethyl)phenyl]propyl]thio]methyl]cyclopropaneacetic acid, monosodium salt.
The empirical formula is C35H35ClNNaO3S, and its molecular weight is 608.18.
The structural formula is:
Montelukast sodium is a hygroscopic, optically active, white to off-white powder. Montelukast sodium is freely soluble in ethanol, methanol, and water and practically insoluble in acetonitrile.
What is Montelukast:
Montelukast is an oral leukotriene receptor antagonist for the treatment of asthma and seasonal allergic rhinitis (hay fever). Leukotrienes are a group of naturally occurring chemicals in the body that promote inflammation in asthma and seasonal allergic rhinitis and in other diseases in which inflammation is important (such as allergy ). They are formed by cells, released, and then bound to other cells, and it is the binding to these other cells that stimulates the cells to promote inflammation. Montelukast works in a manner similar to zafirlukast (Accolate), blocking the binding of some leukotrienes. Unlike zafirlukast, montelukast does not inhibit CYP2C9 or CYP3A4, two enzymes in the liver that are important in breaking down and eliminating many drugs. Therefore, unlike zafirlukast, montelukast is not expected to affect the elimination of other drugs. The safety and effectiveness of montelukast has been demonstrated in children as young as 6 months of age. It was approved by the FDA in 1998.
Montelukast is used to prevent asthma attacks
. Montelukast is also used in the treatment of allergies
Montelukast may also be used for purposes other than those listed in this medication guide.
Do not take montelukast during you are taking
rifampin (Rimactane, Rifadin) or phenobarbital (Luminal, Solfoton).
Montelukast is used for the treatment of asthma and seasonal allergic rhinitis. Montelukast begins working after 3 to 14 days of therapy. Therefore, it should not be used for the treatment of an acute asthmatic attack.
The most common side effects with montelukast are headache, dizziness , abdominal pain , sore throat , and rhinitis (inflammation of the inner lining of the nose). These side effects occur in 1 in 50 to 1 in 7 persons who take montelukast.
CLINICAL PHARMACOLOGY, please click here! ¡ï¡ï
No mortality occurred following single oral doses of montelukast up to 5000 mg/kg in mice (estimated exposure was approximately 250 times the AUC for adults and children at the maximum recommended daily oral dose) and rats (estimated exposure was approximately 170 times the AUC for adults and children at the maximum recommended daily oral dose).
No specific information is available on the treatment of overdosage with SINGULAIR. In chronic asthma studies, montelukast has been administered at doses up to 200 mg/day to adult patients for 22 weeks and, in short-term studies, up to 900 mg/day to patients for approximately a week without clinically important adverse experiences. In the event of overdose, it is reasonable to employ the usual supportive measures; e.g., remove unabsorbed material from the gastrointestinal tract, employ clinical monitoring, and institute supportive therapy, if required.
There have been reports of acute overdosage in pediatric patients in post-marketing experience and clinical studies of up to at least 150 mg/day with SINGULAIR. The clinical and laboratory findings observed were consistent with the safety profile in adults and older pediatric patients. There were no adverse experiences reported in the majority of overdosage reports. The most frequent adverse experiences observed were thirst, somnolence, mydriasis, hyperkinesia, and abdominal pain.
It is not known whether montelukast is removed by peritoneal dialysis or hemodialysis.
DOSAGE AND ADMINISTRATION
SINGULAIR should be taken once daily. For asthma, the dose should be taken in the evening. For seasonal allergic rhinitis, the time of administration may be individualized to suit patient needs.
Patients with both asthma and seasonal allergic rhinitis should take only one tablet daily in the evening.
Adults and Adolescents 15 Years of Age and Older with Asthma or Seasonal Allergic Rhinitis
The dosage for adults and adolescents 15 years of age and older is one 10-mg tablet daily.
Pediatric Patients 6 to 14 Years of Age with Asthma or Seasonal Allergic Rhinitis
The dosage for pediatric patients 6 to 14 years of age is one 5-mg chewable tablet daily. No dosage adjustment within this age group is necessary.
Pediatric Patients 2 to 5 Years of Age with Asthma or Seasonal Allergic Rhinitis
The dosage for pediatric patients 2 to 5 years of age is one 4-mg chewable tablet or one packet of 4-mg oral granules daily.
Pediatric Patients 12 to 23 Months of Age with Asthma
The dosage for pediatric patients 12 to 23 months of age is one packet of 4-mg oral granules daily to be taken in the evening. Safety and effectiveness in pediatric patients younger than 12 months of age have not been established.
Administration of SINGULAIR Oral Granules
SINGULAIR 4-mg oral granules can be administered either directly in the mouth, or mixed with a spoonful of cold or room temperature soft foods; based on stability studies, only applesauce, carrots, rice or ice cream should be used. The packet should not be opened until ready to use. After opening the packet, the full dose (with or without mixing with food) must be administered within 15 minutes. If mixed with food, SINGULAIR oral granules must not be stored for future use. Discard any unused portion. SINGULAIR oral granules are not intended to be dissolved in liquid for administration. However, liquids may be taken subsequent to administration. SINGULAIR oral granules can be administered without regard to the time of meals.