{"ok":true,"entry":{"slug":"isosorbide-mononitrate","kind":"medication","name":"isosorbide mononitrate","aliases":["Imdur","ISMN"],"brands_sg":["Imdur","Imdex"],"class":"nitrate","tags":["heart-bp"],"use_for":"prescribed to prevent angina, not to stop an attack","use_after":"sg label: one 60 mg tablet once daily, not twice","use_duration":null,"take_with":"healthhub: with or without food · not chewed or crushed","pros":["nhs: tablets usually start working within 1 hour","sg label: half a 60 mg tablet keeps slow release","healthhub: regular use cuts how often angina hits"],"cons":["nhs: headache, dizziness, weakness are common","healthhub: not with sildenafil, tadalafil, vardenafil","nhs: alcohol adds to the dizziness and headache"],"dose_note":"the sg imdur durules label (sin01996p) states 'One 60 mg Imdur Durules once daily. The dose may be increased to 120 mg once daily. Imdur Durules should not be administered twice daily'; the nhs gives the same slow-release ceiling ('25mg to 60mg, up to a maximum dose of 120mg, taken once a day') and 120 mg a day for standard tablets, while the us extended-release label adds 'Rarely, 240 mg may be required'; as directed on the label or by your doctor","dosage":null,"ul_status":null,"sg_class":"prescription-only","cautions":["recent heart attack, stroke or head injury — nhs says tell your doctor","low blood pressure, anaemia or glaucoma — nhs says tell your doctor","underactive thyroid — nhs says tell your doctor","surgery coming up — nhs: your doctor may advise stopping it beforehand"],"clashes":[{"src":["healthhub_ismn","nhs_ismn_int"],"note":"healthhub: blood pressure can drop greatly — dizziness, lightheadedness or fainting","with":"sildenafil, tadalafil, vardenafil (and avanafil)"},{"src":["nhs_ismn_int"],"note":"nhs: check with a pharmacist or doctor before starting","with":"riociguat"},{"src":["nhs_ismn_int"],"note":"nhs: blood pressure can fall too far; a dose change may be needed","with":"other blood-pressure or heart medicines"},{"src":["nhs_ismn_int"],"note":"nhs: regular use may make angina or heart failure worse; paracetamol is safe","with":"nsaids such as ibuprofen, aspirin, naproxen"},{"src":["nhs_ismn_int"],"note":"nhs lists them among medicines to check before starting","with":"ergotamine migraine medicines"}],"sources":[{"id":"hsa_register","url":"https://data.gov.sg/datasets/d_767279312753558cbf19d48344577084/view","label":"HSA — Listing of Registered Therapeutic Products (open dataset on data.gov.sg; same register as HSA Infosearch)","quote":"Only 2 isosorbide-5-mononitrate products on the register, both 'Prescription Only': SIN01996P IMDUR DURULES TABLET 60 mg and SIN10515P IMDEX CR TABLET 60 mg, both film-coated oral tablets, ATC C01DA14.","accessed":"2026-08-27"},{"id":"ndf_imdur","url":"https://www.ndf.gov.sg/about-drugs/product-information/sin01996p/","label":"MOH National Drug Formulary — IMDUR DURULES TABLET 60 MG [SIN01996P], SG product information (last updated 28 July 2026)","quote":"PRESCRIPTION ONLY MEDICINES … indicated for prophylactic treatment of angina pectoris … not recommended for … acute attacks … One 60 mg Imdur Durules once daily. The dose may be increased to 120 mg once daily … should not be administered twice daily.","accessed":"2026-08-27"},{"id":"healthhub_ismn","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/isosorbide-mononitrate","label":"HealthHub (MOH Singapore / Pharmaceutical Society of Singapore) — Isosorbide Mononitrate medication information leaflet (reviewed 10 Apr 2026)","quote":"You may take this medication with or without food. The medication may be halved, but do not crush or chew the tablets … can help to reduce the number of angina attacks … Do not take Sildenafil (Viagra®), Tadalafil (Cialis®), Vardenafil (Levitra®).","accessed":"2026-08-27"},{"id":"nhs_ismn_about","url":"https://www.nhs.uk/medicines/isosorbide-mononitrate-dinitrate/about-isosorbide-mononitrate-and-isosorbide-dinitrate/","label":"NHS Medicines A-Z — About isosorbide mononitrate and isosorbide dinitrate (reviewed 27 Aug 2024)","quote":"They're used to prevent angina symptoms (chest pain). They do not work to treat a current angina attack … tablets and capsules usually start to work within 1 hour … Drinking alcohol can increase the effects of these medicines.","accessed":"2026-08-27"},{"id":"nhs_ismn_how","url":"https://www.nhs.uk/medicines/isosorbide-mononitrate-dinitrate/how-and-when-to-take-isosorbide-mononitrate-and-isosorbide-dinitrate/","label":"NHS Medicines A-Z — How and when to take isosorbide mononitrate and isosorbide dinitrate (reviewed 27 Aug 2024)","quote":"isosorbide mononitrate standard tablets – 10mg, taken twice a day, up to a maximum dose of 120mg a day … slow-release tablets or capsules – 25mg to 60mg, up to a maximum dose of 120mg, taken once a day.","accessed":"2026-08-27"},{"id":"nhs_ismn_who","url":"https://www.nhs.uk/medicines/isosorbide-mononitrate-dinitrate/who-can-and-cannot-take-isosorbide-mononitrate-and-isosorbide-dinitrate/","label":"NHS Medicines A-Z — Who can and cannot take isosorbide mononitrate and isosorbide dinitrate (reviewed 27 Aug 2024)","quote":"tell your doctor or pharmacist if you have: any other heart problems, including a recent heart attack · any recent brain or head injuries · ever had a stroke · an underactive thyroid · low blood pressure · anaemia · glaucoma.","accessed":"2026-08-27"},{"id":"nhs_ismn_se","url":"https://www.nhs.uk/medicines/isosorbide-mononitrate-dinitrate/side-effects-of-isosorbide-mononitrate-and-isosorbide-dinitrate/","label":"NHS Medicines A-Z — Side effects of isosorbide mononitrate and isosorbide dinitrate (reviewed 27 Aug 2024)","quote":"common side effects … Headaches … Feeling dizzy, weak, tired or sleepy … Feeling sick (nausea) … Flushing of the face … Do not drink alcohol, as it could make your headaches worse.","accessed":"2026-08-27"},{"id":"nhs_ismn_int","url":"https://www.nhs.uk/medicines/isosorbide-mononitrate-dinitrate/taking-isosorbide-mononitrate-and-isosorbide-dinitrate-with-other-medicines-and-herbal-supplements/","label":"NHS Medicines A-Z — Taking isosorbide mononitrate and isosorbide dinitrate with other medicines and herbal supplements (reviewed 27 Aug 2024)","quote":"medicines for erection problems including sildenafil, avanafil, tadalafil or vardenafil · riociguat … medicines for migraine that contain ergotamine … Do not take non-steroidal anti-inflammatory drugs (NSAIDs) regularly … These may make your angina or heart failure worse.","accessed":"2026-08-27"},{"id":"fda_ismn_er","url":"https://api.fda.gov/drug/label.json?search=openfda.generic_name:%22ISOSORBIDE+MONONITRATE%22&limit=3","label":"FDA / openFDA drug label — Isosorbide mononitrate extended-release tablets (Torrent Pharmaceuticals, effective 11 May 2026)","quote":"The recommended starting dose … is 30 mg … or 60 mg … once daily. After several days, the dosage may be increased to 120 mg … once daily. Rarely, 240 mg may be required … should not be chewed or crushed.","accessed":"2026-08-27"}],"brand_certs":null,"updated_at":"2026-08-29T16:16:23.779398+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."}