• Asthma, including asthma mainly triggered by exercise.
• The medicine can also provide relief from hayfever symptoms in people with asthma who also suffer from hayfever (seasonal allergic rhinitis). Montelukast is used for people whose asthma is not fully controlled by using regular inhaled corticosteroids and short-acting beta agonist relievers such as salbutamol. It is used in addition to these medicines. Montelukast should be taken regularly to prevent asthma attacks. You should continue to take it even when your symptoms are under control. Montelukast 10mg tablets are suitable for adults aged 15 years and over. Montelukast paediatric chewable tablets and granules contain lower doses of montelukast for younger children.

• Adults aged 15 years and over should take one 10mg tablet once daily, in the evening. The tablet can be taken either with or without food.
• You should take this medicine every day, even when your symptoms are under control. Don't stop taking it unless instructed to by your doctor.
• If you forget to take a dose don't worry, just leave out the missed dose and take your next dose as usual. Do not take a double dose to make up for a missed dose.

• This medicine should never be taken to treat an asthma attack because it won't work for this purpose. An asthma attack needs to be treated with a medicine that quickly opens the airways, such as salbutamol or terbutaline. These are known as relievers, and you should make sure you carry your reliever inhaler with you at all times to relieve an asthma attack if it happens.
• Consult your doctor if you need to use your reliever more frequently than normal, or if it becomes less effective at treating attacks, as this may indicate that your asthma is getting worse and your doctor may need to prescribe you another medicine.
• If you find that your asthma improves after starting treatment with this medicine, it is important that you don't stop taking any of your other medicines, in particular any corticosteroid inhalers or tablets, as this will make your symptoms get worse again. This medicine is not a substitute for corticosteroids. However, you may find that you need to use your reliever inhaler less frequently - this is fine and shows your asthma is more under control.
• In very rare cases, people taking leukotriene receptor antagonists have experienced a rare condition known as Churg-Strauss syndrome. Symptoms of this include flu-like symptoms, increasing breathlessness, pins and needles, numbness of the limbs or a rash. You should consult your doctor if you experience any of these symptoms while taking this medicine.

• Read the package insert and/or patient product information sheet that comes with your prescription.

• Rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption (Montelukast 10mg tablets contain lactose).
• Montelukast 10mg tablets are not recommended for children under 15 years of age. Other forms of montelukast are available for treating children - see Montelukast paediatric. This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy. If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

•Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
• The safety of this medicine for use during pregnancy has not been established. It should only be used in pregnancy if considered essential by your doctor. Seek further medical advice from your doctor.
• It is not known if this medicine passes into breast milk. It should only be used by women who are breastfeeding if considered essential by your doctor. Seek further medical advice from your doctor.

•Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
• Headache.
• Abdominal pain.
• Dry mouth.
• Indigestion.
• Nosebleeds.
• Dizziness.
• Drowsiness.
• Pins and needles or numb sensations.
• Difficulty sleeping (insomnia).
• Nightmares.
• Sleepwalking.
• Anxiety.
• Depression.
• Agitation, aggression or hostility.
• Hyperactivity, including restlessness and irritability.
• Seizures.
• Bruising.
• Itching.
• Itchy blistering rash (hives).
• Pain in the muscles and joints.
• Feeling weak, tired or generally unwell.
• Fluid retention, causing swelling (oedema).
• Allergic reactions.
• Problems with attention or memory.
• Increased bleeding tendency.
• Awareness of your heartbeat (palpitations).
• Swelling of the face, tongue or throat (angioedema).
• Skin rashes.
• Inflammation of the liver (hepatitis).
• Hallucinations.
• Feeling disorientated.
• Suicidal thoughts or behaviour.
• Churg-Strauss Syndrome - see warning section above. The side effects listed above may not include all of the side effects reported by the medicine's manufacturer. For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

•You should tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to make sure that the combination is safe. The following medicines may decrease the amount of montelukast in the bloodstream and could make it less effective:
• phenobarbital
• phenytoin
• rifampicin. Gemfibrozil may increase the amount of montelukast in the blood and so could potentially increase the chance of its side effects.

•Read the package insert and/or patient product information sheet that comes with your prescription.
• Most medications should be stored in a dry place away from heat and humidity.
• Some medications also have special instructions for storage. Check for special instructions on your prescription label.
• If your medication needs to be protected from light, it should be stored in a container that filters out light, such as a clean film canister.
• If your medication needs to be refrigerated, and you do not have a fridge available (for example, if you are working outside or on the road all day), try using a cooler with an ice pack. An ordinary cooler found at hardware or sporting goods stores will do.

•Consult your doctor for further instructions and also read the package insert and/or patient product information sheet that comes with your prescription.