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(montelukast sodium)
This product is available as any of the above names but will be referred to
as Singulair throughout this leaflet.
Read all of this leaflet carefully before you start taking this medicine.
 Keep this leaflet. You may need to read it again.
 If you have any further questions, please ask your doctor or pharmacist.
 This medicine has been prescribed for you. Do not pass it on to others.
It may harm them, even if their symptoms are the same as yours.
 If any of the side effects get serious, or if you notice any side effects not
listed in this leaflet, please tell your doctor or pharmacist.
In this leaflet:
1. What Singulair is and what it is used for
2. Before you take Singulair
3. How to take Singulair
4. Possible side effects
5. How to store Singulair
6. Further information


What Singulair is and what it is used for

Singulair is a leukotriene receptor antagonist that blocks substances called
leukotrienes. Leukotrienes cause narrowing and swelling of airways in the
lungs and also cause allergy symptoms. By blocking leukotrienes, Singulair
improves asthma symptoms, helps control asthma and improves seasonal
allergy symptoms (also known as hay fever or seasonal allergic rhinitis).
Your doctor has prescribed Singulair to treat asthma, preventing your
asthma symptoms during the day and night.
 Singulair is used for the treatment of patients who are not adequately
controlled on their medication and need additional therapy.
 Singulair also helps prevent the narrowing of airways triggered by
 In those asthmatic patients in whom Singulair is indicated in asthma,
Singulair can also provide symptomatic relief of seasonal allergic
Your doctor will determine how Singulair should be used depending on the
symptoms and severity of your asthma.
What is asthma?
Asthma is a long-term disease.
Asthma includes:
 difficulty breathing because of narrowed airways. This narrowing of
airways worsens and improves in response to various conditions.
 sensitive airways that react to many things, such as cigarette smoke,
pollen, cold air, or exercise.
 swelling (inflammation) in the lining of the airways.
Symptoms of asthma include: Coughing, wheezing, and chest tightness.
What are seasonal allergies?
Seasonal allergies (also known as hay fever or seasonal allergic rhinitis) are
an allergic response often caused by airborne pollens from trees, grasses
and weeds. The symptoms of seasonal allergies typically may include:
stuffy, runny, itchy nose; sneezing; watery, swollen, red, itchy eyes.


Before you take Singulair

Tell your doctor about any medical problems or allergies you have now or
have had.
Do not take Singulair if you
 are allergic (hypersensitive) to montelukast or any of the other
ingredients of Singulair (see 6. Further information).

Take special care with Singulair
 If your asthma or breathing gets worse, tell your doctor immediately.
 Oral Singulair is not meant to treat acute asthma attacks. If an attack
occurs, follow the instructions your doctor has given you. Always have
your inhaled rescue medicine for asthma attacks with you.
 It is important that you or your child take all asthma medications
prescribed by your doctor. Singulair should not be substituted for other
asthma medications your doctor has prescribed for you.
 Any patient on anti-asthma medicines should be aware that if you
develop a combination of symptoms such as a flu-like illness, pins and
needles or numbness of arms or legs, worsening of pulmonary
symptoms, and/or rash, you should consult your doctor.
 You should not take acetyl‑salicylic acid (aspirin) or anti-inflammatory
medicines (also known as non-steroidal anti-inflammatory drugs or
NSAIDs) if they make your asthma worse.
Use in children
For children 2 to 5 years old, Singulair Paediatric 4 mg chewable tablets and
Singulair Paediatric 4 mg granules are available.
For children 6 to 14 years old, Singulair Paediatric 5 mg chewable tablets
are available.
Taking other medicines
Some medicines may affect how Singulair works, or Singulair may affect
how other medicines work.
Please tell your doctor or pharmacist if you are taking or have recently taken
other medicines, including those obtained without a prescription.
Tell your doctor if you are taking the following medicines before starting
 phenobarbital (used for treatment of epilepsy)
 phenytoin (used for treatment of epilepsy)
 rifampicin (used to treat tuberculosis and some other infections)
 gemfibrozil (used for treatment of high lipid levels in plasma)
Taking Singulair with food and drink
Singulair 10 mg may be taken with or without food.
Pregnancy and breast-feeding
Use in pregnancy
Women who are pregnant or intend to become pregnant should consult their
doctor before taking Singulair. Your doctor will assess whether you can
take Singulair during this time.
Use in breast-feeding
It is not known if Singulair appears in breast milk. You should consult your
doctor before taking Singulair if you are breast-feeding or intend to
Driving and using machines
Singulair is not expected to affect your ability to drive a car or operate
machinery. However, individual responses to medication may vary. Certain
side effects (such as dizziness and drowsiness) that have been reported
very rarely with Singulair may affect some patients’ ability to drive or operate
Important information about some of the ingredients of Singulair
Singulair 10 mg film-coated tablets contain lactose.
If you have been told by your doctor that you have an intolerance to some
sugars, contact your doctor before taking this medicinal product.


How to take Singulair
You should take only one tablet of Singulair once a day as prescribed by
your doctor.
It should be taken even when you have no symptoms or have an acute
asthma attack.
Always take Singulair as your doctor has told you. You should check
with your doctor or pharmacist if you are not sure.
To be taken by mouth.

The following is a translation of the days of the week on the blister strip:-






Wednesday Thursday







For adults and adolescents 15 years of age and older:
One 10 mg tablet to be taken daily in the evening.
Singulair 10 mg may be taken with or without food.
If you are taking Singulair, be sure that you do not take any other
products that contain the same active ingredient, montelukast.
If you take more Singulair than you should
Contact your doctor immediately for advice.
There were no side effects reported in the majority of overdose reports. The
most frequently occurring symptoms reported with overdose in adults and
children included abdominal pain, sleepiness, thirst, headache, vomiting,
and hyperactivity.
If you forget to take Singulair
Try to take Singulair as prescribed. However, if you miss a dose, just
resume the usual schedule of one tablet once daily.
Do not take a double dose to make up for a forgotten dose.
If you stop taking Singulair
Singulair can treat your asthma only if you continue to take it.
It is important to continue taking Singulair for as long as your doctor
prescribes. It will help control your asthma.
If you have any further questions on the use of this product, ask your doctor
or pharmacist.


hepatitis (inflammation of the liver) (Very rare)
rash (Common); bruising, itching, hives

Possible side effects

Like all medicines, Singulair can cause side effects, although not
everybody gets them.

(Uncommon); tender red lumps under the skin most commonly on your
shins (erythema nodosum), severe skin reactions (erythema multiforme)
that may occur without warning (Very rare)
 joint or muscle pain, muscle cramps (Uncommon)
 fever (Common); weakness/tiredness, feeling unwell, swelling
In asthmatic patients treated with montelukast, very rare cases of a
combination of symptoms such as flu-like illness, pins and needles or
numbness of arms and legs, worsening of pulmonary symptoms and/or rash
(Churg-Strauss syndrome) have been reported.
You must tell your doctor right away if you get one or more of these
Reporting of side effects
If you get any side effects, talk to your doctor, pharmacist or nurse. This
includes any possible side effects not listed in this leaflet. You can also
report side effects directly (see details below). By reporting side effects you
can help provide more information on the safety of this medicine.
Yellow Card Scheme at: www.




In clinical studies with Singulair 10 mg film-coated tablets, the most
commonly reported side effects (occurring in at least 1 of 100 patients and
less than 1 of 10 patients treated) thought to be related to Singulair were:
 abdominal pain
 headache
These were usually mild and occurred at a greater frequency in patients
treated with Singulair than placebo (a pill containing no medication).
The frequency of possible side effects listed below is defined using the
following convention:
Very common (affects at least 1 user in 10)
Common (affects 1 to 10 users in 100)
Uncommon (affects 1 to 10 users in 1,000)
Rare (affects 1 to 10 users in 10,000)
Very rare (affects less than 1 user in 10,000)
Additionally, while the medicine has been on the market, the following have
been reported:
 upper respiratory infection (Very common)
 increased bleeding tendency (Rare)
 allergic reactions including swelling of the face, lips, tongue, and/or
throat which may cause difficulty in breathing or swallowing
 behaviour and mood related changes [dream abnormalities, including
nightmares, trouble sleeping, sleep walking, irritability, feeling anxious,
restlessness, agitation including aggressive behaviour or hostility,
depression (Uncommon); tremor, disturbance in attention, memory
impairment (Rare); hallucinations, disorientation, suicidal thoughts and
actions (Very rare)]
 dizziness, drowsiness, pins and needles/numbness, seizure
 palpitations (Rare)
 nosebleed (Uncommon), swelling (inflammation) of the lungs (Very rare)
 diarrhoea, nausea, vomiting (Common); dry mouth, indigestion


How to store Singulair
Keep out of the sight and reach of children.
Store in the original container to protect from moisture and light.
Do not put the tablets into another container, as they might get mixed
up. Do not remove the tablet from the blister pack until you are ready to
take it. Do not take the tablets if they have passed the expiry date,
which is clearly marked on the carton or blister label.
If your doctor tells you to stop taking these tablets, please take them
back to the pharmacist for safe disposal. Only keep the tablets if your
doctor tells you to.
If the tablets become discoloured or show any other signs of
deterioration, consult your pharmacist who will tell you what to do.
Medicines should not be disposed of via wastewater or household
waste. Ask your pharmacist how to dispose of medicines no longer
required. These measures will help to protect the environment.

Further information

What Singulair contains
 Active Ingredient: The active ingredient in Singulair is montelukast
sodium. Each tablet contains 10mg of montelukast (as montelukast
 Other ingredients: microcrystalline cellulose, lactose monohydrate,
croscarmellose sodium, hydroxypropylcellulose (E463) and magnesium
 Tablet coating: hypromellose, hydroxypropylcellulose (E463), titanium
dioxide (E171) , red and yellow ferric oxide (E172) and carnauba wax.
What Singulair looks like and the contents of the pack
The tablets are supplied as beige, rounded square, film-coated tablets
with ‘117’ engraved on one side and plain on the other side.
Singulair is available in calendar blister packs containing 28 tablets.
Singulair is manufactured by Merck Sharp & Dohme Ltd., Shotton Lane,
Cramlington, United Kingdom and is procured from within the EU by the
Product Licence holder: G.Pharma Ltd., Salford M50 2PU.
PL 16369/1240
SINGULAIR 10mg Tablets



Singulair is a registered trademark of Merck & Co., Inc., Whitehouse
Station, NJ, USA.

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Further information

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