{"ok":true,"entry":{"slug":"hydrochlorothiazide","kind":"medication","name":"hydrochlorothiazide","aliases":["HCTZ","Dichlotride"],"brands_sg":["Di-Ertride","Apo-Hydrochlorothiazide"],"class":"thiazide diuretic","tags":["heart-bp"],"use_for":"prescribed for excess fluid and raised blood pressure","use_after":"healthhub: a once-a-day dose is taken in the morning","use_duration":null,"take_with":"water · healthhub: a second daily dose sits before 4pm","pros":["healthhub: often a single dose each day","healthhub: works on the kidneys to shed water and salt","fda label: usual bp start is 25 mg once daily"],"cons":["healthhub: more urine, dry mouth, thirst, dehydration","healthhub: can lower blood potassium","healthhub: sun-sensitive; a rare skin-cancer signal"],"dose_note":"the us fda label for single-ingredient hydrochlorothiazide tablets states 'For Edema - The usual adult dosage is 25 to 100 mg daily as a single or divided dose' and, for hypertension, 'The usual initial dose in adults is 25 mg daily … may be increased to 50 mg daily' — 100 mg a day is that label's stated ceiling, and it adds that 'Doses above 50 mg are often associated with marked reductions in serum potassium'. sg-registered single-ingredient tablets are 25 mg and 50 mg. in singapore the prescriber sets the dose.","dosage":null,"ul_status":null,"sg_class":"prescription-only","cautions":["kidney problems, gout, or lupus (healthhub)","an allergy to sulfonamide medicines such as bactrim (healthhub)","pregnant, planning pregnancy or breastfeeding (healthhub)","past skin cancer or immune-suppressing medicines (healthhub)"],"clashes":[{"src":["fda_hctz_interactions"],"note":"fda label: 'Generally should not be given with diuretics' — diuretics reduce lithium clearance and add a high risk of lithium toxicity","with":"lithium"},{"src":["fda_hctz_interactions"],"note":"fda label: an nsaid can reduce the diuretic, natriuretic and antihypertensive effects of thiazide diuretics","with":"nsaids such as ibuprofen"},{"src":["fda_hctz_interactions"],"note":"fda label: these resins bind hydrochlorothiazide and reduce its absorption by up to 85 and 43 percent","with":"cholestyramine, colestipol"},{"src":["fda_hctz_interactions"],"note":"fda label: dosage adjustment of the antidiabetic drug may be required","with":"insulin and oral diabetes medicines"},{"src":["fda_hctz_interactions"],"food":true,"note":"fda label: potentiation of orthostatic hypotension may occur","with":"alcohol, barbiturates or narcotics"}],"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 locally at /tmp/hsa_all.json and filtered offline)","quote":"All 30 hydrochlorothiazide-containing rows carry Forensicclassification 'Prescription Only'; only 3 are single-ingredient — SIN00108P DI-ERTRIDE TABLET 25 mg · SIN03675P APO-HYDROCHLOROTHIAZIDE 50 mg · SIN03676P APO-HYDROCHLOROTHIAZDE 25 mg","accessed":"2026-08-27"},{"id":"hh_hctz_uses","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/hydrochlorothiazide","label":"HealthHub (National Medication Information workgroup, SG) — Hydrochlorothiazide: what is this medication for","quote":"Hydrochlorothiazide belongs to a class of medications called Diuretics. It works on your kidneys to get rid of extra water and salts in your body. This medication is used to remove excess fluid from your body.","accessed":"2026-08-27"},{"id":"hh_hctz_howto","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/hydrochlorothiazide","label":"HealthHub — Hydrochlorothiazide: how should I take or use this medication","quote":"If you are taking one dose a day, take it in the morning … take the second dose before 4pm so that you do not need to wake up often at night to pass urine.","accessed":"2026-08-27"},{"id":"hh_hctz_precautions","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/hydrochlorothiazide","label":"HealthHub — Hydrochlorothiazide: what precautions should I take","quote":"You are allergic to any other medications, especially sulfonamide medicines (e.g. Bactrim) … You have any problems with the way your kidneys work … You have gout … You have lupus or history of lupus","accessed":"2026-08-27"},{"id":"hh_hctz_side","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/hydrochlorothiazide","label":"HealthHub — Hydrochlorothiazide: common side effects","quote":"Passing urine more often, dry mouth, increased thirst … Too much water loss may result in dehydration … This medication may cause potassium loss … More sensitive to sunlight, skin rash","accessed":"2026-08-27"},{"id":"hh_hctz_serious","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/hydrochlorothiazide","label":"HealthHub — Hydrochlorothiazide: rare but serious side effects","quote":"Very rarely, this medication may be linked to the increased risk of Non-melanoma skin cancer … taking higher doses of this medication for long periods … is linked to a very small risk","accessed":"2026-08-27"},{"id":"fda_hctz_indications","url":"https://api.fda.gov/drug/label.json?search=openfda.brand_name.exact:%22Hydrochlorothiazide%22&limit=1","label":"US FDA label for Hydrochlorothiazide tablets, Indications and Usage, via openFDA drug/label.json (effective 2023-12-25)","quote":"indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis … indicated in the management of hypertension either as the sole therapeutic agent or to enhance the effectiveness of other antihypertensive drugs","accessed":"2026-08-27"},{"id":"fda_hctz_dose","url":"https://api.fda.gov/drug/label.json?search=openfda.brand_name.exact:%22Hydrochlorothiazide%22&limit=1","label":"US FDA label for Hydrochlorothiazide tablets, Dosage and Administration, via openFDA drug/label.json (effective 2023-12-25)","quote":"For Edema - The usual adult dosage is 25 to 100 mg daily as a single or divided dose … For Control Of Hypertension … 25 mg daily … may be increased to 50 mg daily","accessed":"2026-08-27"},{"id":"fda_hctz_interactions","url":"https://api.fda.gov/drug/label.json?search=openfda.brand_name.exact:%22Hydrochlorothiazide%22&limit=1","label":"US FDA label for Hydrochlorothiazide tablets, Precautions — Drug Interactions, via openFDA drug/label.json (effective 2023-12-25)","quote":"Lithium Generally should not be given with diuretics … add a high risk of lithium toxicity … cholestyramine or colestipol resins bind the hydrochlorothiazide and reduce its absorption … by up to 85 and 43 percent","accessed":"2026-08-27"}],"brand_certs":null,"updated_at":"2026-08-29T16:16:21.812539+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."}