{"ok":true,"entry":{"slug":"diltiazem","kind":"medication","name":"diltiazem","aliases":["Herbesser"],"brands_sg":["Herbesser"],"class":"calcium channel blocker","tags":["heart-bp"],"use_for":"healthhub: irregular heartbeats; also lowers blood pressure","use_after":"healthhub: with or without food","use_duration":null,"take_with":"healthhub: grapefruit or its juice may raise side effects","pros":["healthhub: taken with or without food","sg label: usual adult dose 30 mg three times a day","sg label: also indicated for variant angina pectoris"],"cons":["healthhub: leg swelling, headache, constipation","healthhub: dizziness on standing; slower heart rate","healthhub: very rarely, liver problems"],"dose_note":"the singapore label for herbesser 60 tablet states, for angina pectoris, 'The usual adult dosage for oral use is 30 mg of diltiazem hydrochloride three times a day (90 mg/day). The dosage may be increased to 60 mg three times a day (180 mg/day), if necessary', and for mild to moderate essential hypertension '30 to 60 mg of diltiazem hydrochloride three times a day (90 – 180 mg/day)'. that 180 mg/day ceiling belongs to the immediate-release tablet only; the sustained-release herbesser 90 sr, r100 and r200 capsules carry their own dosing, which was not read. in singapore the prescriber sets the dose.","dosage":null,"ul_status":null,"sg_class":"prescription-only","cautions":["sg label contraindication: severe congestive heart failure","sg label contraindication: 2nd/3rd-degree av block or sick sinus syndrome","sg label contraindication: pregnant, or possibly pregnant","healthhub: other medicines that slow the heart rate"],"clashes":[{"src":["hh_dil_avoid"],"food":true,"note":"healthhub: may interact and increase the risk of side-effects","with":"grapefruit and grapefruit juice"},{"src":["hh_dil_hr"],"note":"healthhub: these also slow the heart rate — regular check-ups advised","with":"digoxin, beta blockers, amiodarone"},{"src":["ndf_herb_ci"],"note":"listed as a contraindication on the sg herbesser label","with":"ivabradine hydrochloride"}],"sources":[{"id":"hsa_register","url":"https://data.gov.sg/datasets/d_767279312753558cbf19d48344577084/view","label":"HSA — Listing of Registered Therapeutic Products (data.gov.sg open dataset, 5,511 rows, cached in full and filtered locally)","quote":"All 5 registered diltiazem products are HERBESSER and every row reads Forensicclassification 'Prescription Only' — SIN00428P HERBESSER TABLET 30 mg · SIN00430P HERBESSER 60 TABLET 60 mg · SIN06791P HERBESSER 90 SR CAPSULE · SIN10061P HERBESSER R200 CAPSULES 200 mg","accessed":"2026-08-27"},{"id":"hh_dil_uses","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/diltiazem","label":"HealthHub (National Medication Information workgroup, SG) — Diltiazem: what is this medication for","quote":"Diltiazem is used in the treatment of certain heart conditions such as irregular heartbeats. It may also be used to lower your blood pressure by relaxing and widening blood vessels.","accessed":"2026-08-27"},{"id":"hh_dil_admin","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/diltiazem","label":"HealthHub — Diltiazem: how should I take this medication","quote":"Do not stop taking your medication without checking with your healthcare professional. You may take this medication with or without food.","accessed":"2026-08-27"},{"id":"hh_dil_se","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/diltiazem","label":"HealthHub — Diltiazem: common side effects","quote":"Some side effects may include: Leg swelling; Headache; Constipation (difficulty in passing stools); Dizziness and lightheadedness, especially when you get up from a lying or sitting position … Decreased heart rate","accessed":"2026-08-27"},{"id":"hh_dil_rare","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/diltiazem","label":"HealthHub — Diltiazem: rare but serious side effects","quote":"Very rarely, Diltiazem may cause liver problems … Liver injury - Dark brown urine, light coloured stools (pale grey/ clay coloured), nausea, vomiting, loss of appetite, yellowing of skin or eyes","accessed":"2026-08-27"},{"id":"hh_dil_avoid","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/diltiazem","label":"HealthHub — Diltiazem: what food or medication should I avoid","quote":"Avoid taking grapefruit, or grapefruit juice as they may interact with your medication and increase the risk of side-effects.","accessed":"2026-08-27"},{"id":"hh_dil_hr","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/diltiazem","label":"HealthHub — Diltiazem: precautions (heart-rate-slowing medicines)","quote":"This medicine can cause the heart rate to be slower and should be used with caution with other medicines that slow the heart rate e.g. digoxin, beta blockers and amiodarone.","accessed":"2026-08-27"},{"id":"ndf_herb_ind","url":"https://www.ndf.gov.sg/about-drugs/product-information/sin00430p/","label":"Singapore National Drug Formulary (HSA/MOH) — HERBESSER 60 TABLET 60 MG [SIN00430P], Indications","quote":"INDICATIONS: Angina pectoris, variant angina pectoris; Essential hypertension (mild to moderate)","accessed":"2026-08-27"},{"id":"ndf_herb_dose","url":"https://www.ndf.gov.sg/about-drugs/product-information/sin00430p/","label":"Singapore National Drug Formulary — HERBESSER 60 TABLET 60 MG [SIN00430P], Dosage and Administration","quote":"The usual adult dosage for oral use is 30 mg of diltiazem hydrochloride three times a day (90 mg/day). The dosage may be increased to 60 mg three times a day (180 mg/day), if necessary.","accessed":"2026-08-27"},{"id":"ndf_herb_ci","url":"https://www.ndf.gov.sg/about-drugs/product-information/sin00430p/","label":"Singapore National Drug Formulary — HERBESSER 60 TABLET 60 MG [SIN00430P], Contraindications","quote":"Patients with severe congestive heart failure … Patients with 2nd- or 3rd-degree atrioventricular block or sick sinus syndrome … Pregnant women or women who may possibly be pregnant … Patients receiving ivabradine hydrochloride.","accessed":"2026-08-27"}],"brand_certs":null,"updated_at":"2026-08-29T16:16:18.585742+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."}