{"ok":true,"entry":{"slug":"montelukast","kind":"medication","name":"montelukast","aliases":["Singulair","Montek"],"brands_sg":["Singulair","Montelukast Sandoz","Montelair","Regulair","M-Kast"],"class":"leukotriene receptor antagonist","tags":["respiratory","allergy"],"use_for":"preventing asthma symptoms and allergic rhinitis","use_after":"once a day — nhs: most people take it in the evening","use_duration":null,"take_with":"with or without food · chewables apart from meals","pros":["one tablet a day — nhs: usual adult dose is 10 mg","covers asthma and allergic rhinitis together","plain tablets: with or without food (nhs)"],"cons":["prescription-only in sg — not sold over the counter","mood, sleep and behaviour changes are reported","not for a sudden asthma attack (healthhub)"],"dose_note":"nhs states 'The usual dose for adults and children aged 15 years old and over is one 10mg tablet once a day' and 'Never take more than 1 dose a day'; singapore registrations run 4 mg and 5 mg chewable tablets, 4 mg granules and 10 mg tablets, all prescription only; nhs also notes montelukast is usually taken in the evening — as directed on the label or by your doctor or pharmacist","dosage":null,"ul_status":null,"sg_class":"prescription-only","cautions":["any past or present mental health condition — healthhub says say so","mood, sleep or behaviour changes — nhs says call a doctor or 111","aspirin-sensitive asthma — healthhub says keep avoiding aspirin/nsaids","a prescribed steroid inhaler — healthhub says not to stop it suddenly"],"clashes":[{"src":["healthhub_mont_interact"],"note":"healthhub: with aspirin sensitivity or aspirin-sensitive asthma, keep avoiding them while on montelukast","with":"aspirin and other anti-inflammatory medicines (nsaids)"},{"src":["healthhub_mont_interact"],"note":"healthhub: it is not stopped suddenly when montelukast is started; the doctor reduces it gradually if needed","with":"a prescribed steroid inhaler for asthma control"}],"sources":[{"id":"healthhub_mont","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/montelukast","label":"HealthHub (MOH Singapore) — Montelukast, uses section","quote":"Montelukast is used to treat and prevent asthma and allergic rhinitis … Montelukast blocks certain substances in the body called leukotrienes that cause inflammation of the airways and nose in asthma, or allergic rhinitis","accessed":"2026-08-27"},{"id":"healthhub_mont_warn","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/montelukast","label":"HealthHub (MOH Singapore) — Montelukast, precautions and neuropsychiatric warning sections","quote":"You currently have, or previously had, any mental health conditions … Montelukast should not be used to treat sudden asthma attacks. You should have your rescue inhaler available for emergency use … neuropsychiatric side effects have been reported with Montelukast","accessed":"2026-08-27"},{"id":"healthhub_mont_interact","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/montelukast","label":"HealthHub (MOH Singapore) — Montelukast, administration and food/medicine interaction sections","quote":"if you are sensitive to aspirin or have aspirin-sensitive asthma, continue to avoid aspirin and other anti-inflammatory medications while taking montelukast … Do not suddenly stop taking your prescribed steroid inhaler for asthma control when starting this medication","accessed":"2026-08-27"},{"id":"nhs_mont_how","url":"https://www.nhs.uk/medicines/montelukast/how-and-when-to-take-montelukast/","label":"NHS — How and when to take montelukast, dosage section (brand name: Singulair)","quote":"The usual dose for adults and children aged 15 years old and over is one 10mg tablet once a day … Most people take montelukast once a day in the evening … Never take more than 1 dose a day","accessed":"2026-08-27"},{"id":"nhs_mont_how_food","url":"https://www.nhs.uk/medicines/montelukast/how-and-when-to-take-montelukast/","label":"NHS — How and when to take montelukast, 'How to take it' and 'How long to take it for' sections","quote":"You can take montelukast non-chewable tablets with or without food … It's important to take chewable tablets at least 1 hour before food, or 2 hours after food … Do not stop taking montelukast without speaking to your doctor first","accessed":"2026-08-27"},{"id":"nhs_mont_se","url":"https://www.nhs.uk/medicines/montelukast/side-effects-of-montelukast/","label":"NHS — Side effects of montelukast, common side effects (brand name: Singulair)","quote":"These common side effects of montelukast happen in more than 1 in 100 people … Diarrhoea … High temperature … Headaches … Stomach pain … Feeling or being sick … A mild rash","accessed":"2026-08-27"},{"id":"nhs_mont_se_serious","url":"https://www.nhs.uk/medicines/montelukast/side-effects-of-montelukast/","label":"NHS — Side effects of montelukast, serious side effects section","quote":"Call your doctor or call 111 immediately if: you notice mood changes and you become anxious, depressed or aggressive … hallucinations … new problems with your sleep … Call 999 or go to A&E if you have thoughts about harming yourself","accessed":"2026-08-27"},{"id":"hsa_register_mont","url":"https://data.gov.sg/datasets/d_767279312753558cbf19d48344577084/view","label":"HSA register of therapeutic products (data.gov.sg open data d_767279312753558cbf19d48344577084, datastore_search API) — montelukast rows","quote":"Productname: SINGULAIR TABLET 10 mg … Forensicclassification: Prescription Only … Productname: SINGULAIR CHEWABLE TABLET 4 mg … Prescription Only … Productname: Lukakline Chewable Tablet 5mg … Prescription Only … SINGULAIR ORAL GRANULES 4 mg/sachet","accessed":"2026-08-27"}],"brand_certs":null,"updated_at":"2026-08-29T16:16:26.600885+08:00"},"disclaimer":"kozen-x is not a medical device and does not give medical advice. it lists what published sources have written down. absence of a record is not the same as safe."}