Package Leaflet: Information for the User
Singulair 4mg Chewable Tablets
montelukast
Read all of this leaflet carefully before giving this medicine to your child, because it contains important information.
Contents of the Package Leaflet
What is Singulair
Singulair is a leukotriene receptor antagonist that blocks substances called leukotrienes.
How Singulair works
Leukotrienes cause narrowing and swelling of the airways in the lungs. By blocking leukotrienes, Singulair improves asthma symptoms and helps control asthma.
When to use Singulair
Your doctor has prescribed Singulair to treat your child's asthma and prevent asthma symptoms during the day and night.
Depending on your child's symptoms and the severity of their asthma, your doctor will determine how to use Singulair.
What is asthma?
Asthma is a chronic disease.
Asthma includes:
Asthma symptoms include: Cough, wheezing, and chest congestion.
Tell your doctor about any allergy or medical problem your child has now or has had.
Do not give Singulair to your child
Warnings and precautions
Consult your doctor or pharmacist before giving Singulair to your child.
Several neuropsychiatric events (e.g., changes in behavior and mood-related, depression, and suicidal tendencies) have been reported in patients of all ages treated with montelukast (see section 4). If your child develops these symptoms while taking montelukast, they should contact their doctor.
Children and adolescents
Do not give this medicine to children under 2 years of age.
For pediatric patients under 18 years of age, other formulations of this medicine are available based on the age range.
Other medicines and Singulair
Tell your doctor or pharmacist if your child is taking, has recently taken, or might take any other medicines, including those obtained without a prescription.
Some medicines may affect the way Singulair works, or Singulair may affect the way other medicines work that your child is using.
Before taking Singulair, tell your doctor if your child is taking the following medicines:
Taking Singulair with food and drinks
Singulair 4 mg chewable tablets should not be taken with food; they should be taken at least 1 hour before or 2 hours after food.
Pregnancy and breastfeeding
This subsection is not applicable to Singulair 4 mg chewable tablets, as its use is indicated in children between 2 and 5 years of age.
Driving and using machines
This subsection is not applicable to Singulair 4 mg chewable tablets, as its use is indicated in children between 2 and 5 years of age. However, the following information is important for the active ingredient, montelukast.
Singulair is not expected to affect your child's ability to drive a car or operate machinery. However, individual responses to the medicine may vary. Certain side effects (such as dizziness and drowsiness) that have been reported with Singulair may affect your child's ability to drive or operate machinery.
Singulair 4mg chewable tablets contain aspartame, sodium, and benzyl alcohol
This medicine contains 1.2 mg of aspartame in each 4 mg chewable tablet, equivalent to 0.674 mg of phenylalanine. Aspartame is a source of phenylalanine that may be harmful if your child has phenylketonuria (PKU), a rare genetic disorder in which phenylalanine accumulates because the body cannot eliminate it properly.
This medicine contains less than 23 mg of sodium (1 mmol) per tablet; this is essentially "sodium-free".
This medicine contains up to 0.36 mg of benzyl alcohol in each tablet. Benzyl alcohol may cause allergic reactions.
Consult your doctor or pharmacist if your child has liver or kidney disease. This is because large amounts of benzyl alcohol can accumulate in the body and cause side effects (metabolic acidosis).
Follow exactly the administration instructions of this medicine given by your doctor or pharmacist for your child. In case of doubt, consult your doctor or pharmacist again.
For children from 2 to 5years of age:
The recommended dose is one 4 mg chewable tablet daily in the evening.
If your child is taking Singulair, ensure they do not take any other medicine that contains the same active ingredient, montelukast.
This medicine is taken orally.
The tablets should be chewed before swallowing.
Singulair 4 mg chewable tablets should not be taken with food; they should be taken at least 1 hour before or 2 hours after food.
If your child takes more Singulair than they should
Seek help from your child's doctor immediately.
In most cases of overdose, no side effects were reported. The symptoms that occurred most frequently in overdose in adults and children were abdominal pain, drowsiness, thirst, headache, vomiting, and hyperactivity.
Consult your doctor, pharmacist, or call the Toxicology Information Service, phone 91.562.04.20, indicating the medicine and the amount taken. It is recommended to take the packaging and the package leaflet of the medicine to the healthcare professional.
If you forget to give Singulair to your child
Try to give Singulair as prescribed. However, if your child forgets a dose, just resume the usual routine of one chewable tablet once a day.
Do not give a double dose to make up for forgotten doses.
If your child stops taking Singulair
Singulair can only treat your child's asthma if they continue taking it.
It is essential that your child continues taking Singulair for as long as their doctor prescribes it. It will help control your child's asthma.
If you have any other questions about the use of this medicine, ask your child's doctor or pharmacist.
Like all medicines, this medicine can cause side effects, although not everybody gets them.
In clinical trials conducted with Singulair 4 mg chewable tablets, the side effects related to the administration of the medicine and reported most frequently (may affect up to 1 in 10 people) were:
Additionally, the following side effects were reported in clinical trials with Singulair 10 mg film-coated tablets and 5 mg chewable tablets:
These side effects were generally mild and occurred with a higher frequency in patients treated with Singulair than with placebo (a pill that does not contain medicine).
Serious side effects
Consult your doctor immediatelyif you observe any of the following side effects in your child, which may be serious and your child may need urgent medical treatment.
Uncommon (may affect up to 1 in 100 people):
Rare (may affect up to 1 in 1,000 people):
Very rare (may affect up to 1 in 10,000 people):
Other side effects reported during the post-marketing period of the medicine
Very common (may affect more than 1 in 10 people):
Common (may affect up to 1 in 10 people):
Uncommon (may affect up to 1 in 100 people):
Rare (may affect up to 1 in 1,000 people):
Very rare (may affect up to 1 in 10,000 people):
Reporting of side effects:
If your child experiences any side effects, consult your doctor or pharmacist, even if they are not listed in this leaflet. You can also report them directly through the Spanish Medicines Surveillance System for Human Use: https://www.notificaram.es. By reporting side effects, you can help provide more information on the safety of this medicine.
Composition of Singulair
mannitol (E-421), microcrystalline cellulose, hypromellose (E-463), red iron oxide (E-172), sodium croscarmellose, cherry flavor that contains benzyl alcohol (E-1519), aspartame (E-951), and magnesium stearate.
Appearance of the product and pack contents
Singulair 4 mg chewable tablets are pink, oval, biconvex, with SINGULAIR engraved on one side and MSD 711 on the other.
Blister packs in packs of: 7, 10, 14, 20, 28, 30, 50, 56, 98, 100, 140, and 200 tablets.
Blister packs (unit dose) in packs of: 49x1, 50x1, and 56x1 tablets.
Not all pack sizes may be marketed.
Marketing authorization holder and manufacturer
Marketing authorization holder
Organon Salud, S.L.
Paseo de la Castellana, 77
28046 Madrid
Spain
Tel.: 915911279
Manufacturer
Merck Sharp & Dohme, B.V.
Waarderweg 39
2031 BN, Haarlem
Netherlands
or
Organon Heist bv
Industriepark 30
2220 Heist-op-den-Berg
Belgium
This medicine is authorized in the Member States of the European Economic Area under the following names:
Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, Slovenia, Spain, Sweden
Singulair
Date of last revision of this leaflet:04/2023.
Detailed and updated information on this medicine is available on the website of the Spanish Agency for Medicines and Health Products (AEMPS) http://www.aemps.gob.es/
The average price of SINGULAIR 4 mg CHEWABLE TABLETS in October, 2025 is around 16.84 EUR. Prices may vary depending on the region, pharmacy, and whether a prescription is required. Always check with a local pharmacy or online source for the most accurate information.