{"ok":true,"entry":{"slug":"nitrofurantoin","kind":"medication","name":"nitrofurantoin","aliases":["Macrobid","Furadantin"],"brands_sg":["AA Pharma Nitrofurantoin"],"class":"urinary antibiotic","tags":["antibiotic"],"use_for":"prescribed for lower urinary tract infections","use_after":"nhs: usually 3 to 7 days to treat a uti","use_duration":null,"take_with":"nhs: with or after a meal or snack · swallowed whole","pros":["nhs: concentrated in pee, where the infection is","nhs: alcohol is allowed while taking it","nhs: most people feel better within a few days"],"cons":["fda: nausea 8%, headache 6% in macrobid trials","nhs: pee may turn dark yellow or brown","fda: rare lung, liver and nerve harm, some fatal"],"dose_note":"the us macrobid (slow-release) label states 'Adults and Pediatric Patients Over 12 Years: One 100 mg capsule every 12 hours for seven days'; for the plain tablets registered in singapore the nhs gives the upper regimen as '100mg, taken as standard tablets or capsules, 4 times a day, for severe infections', with 50–100 mg once a night for prevention; as directed on the label or by your doctor","dosage":null,"ul_status":null,"sg_class":"prescription-only","cautions":["kidney problems — fda label: creatinine clearance under 60 ml/min is a contraindication","g6pd deficiency — healthhub and nhs both say to tell your doctor","38 to 42 weeks pregnant, in labour, or a baby under 1 month — fda: contraindicated","lung, liver or nerve problems, anaemia, diabetes — nhs says tell your doctor"],"clashes":[{"src":["fda_macrobid","healthhub_nitro","nhs_nitro_int"],"note":"fda: magnesium trisilicate cuts the rate and extent of absorption","with":"magnesium-containing antacids"},{"src":["fda_macrobid"],"note":"fda: blood levels rise (more toxicity) while urine levels fall (less effect)","with":"probenecid or sulfinpyrazone"},{"src":["nhs_nitro_int"],"note":"nhs lists them among medicines that do not mix well","with":"quinolone antibiotics (ciprofloxacin, norfloxacin, others)"},{"src":["nhs_nitro_int"],"note":"nhs: may not work properly; the injected vaccine is unaffected","with":"oral typhoid vaccine"}],"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 nitrofurantoin products on the register, both 'Prescription Only': SIN00290P AA PHARMA NITROFURANTOIN TABLET 100 mg and SIN00439P AA PHARMA NITROFURANTOIN TABLET 50 mg, both plain oral tablets, ATC J01XE01.","accessed":"2026-08-27"},{"id":"ndf_nitro","url":"https://www.ndf.gov.sg/about-drugs/product-information/sin00290p/","label":"MOH National Drug Formulary — AA PHARMA NITROFURANTOIN TABLET 100 MG [SIN00290P], SG product information (last updated 28 July 2026)","quote":"NITROFURANTOIN - 100 MG … Dosage Form: TABLET … Forensic Classification: PRESCRIPTION ONLY MEDICINES … Prescription-only Medicines with Exemptions for Supply without Prescription: NA","accessed":"2026-08-27"},{"id":"healthhub_nitro","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/nitrofurantoin","label":"HealthHub (MOH Singapore / Pharmaceutical Society of Singapore) — Nitrofurantoin medication information leaflet (reviewed 24 Apr 2026)","quote":"an antibiotic commonly used in the treatment of urinary tract infections … Take this medication with or after food … Inform your healthcare professional if you have Glucose-6-Phosphate-Dehydrogenase (G6PD) deficiency … may also cause your urine to turn dark yellow or brown.","accessed":"2026-08-27"},{"id":"nhs_nitro_about","url":"https://www.nhs.uk/medicines/nitrofurantoin/about-nitrofurantoin/","label":"NHS Medicines A-Z — About nitrofurantoin (brand name: Macrobid; reviewed 6 Jan 2026)","quote":"your body quickly filters it out of your blood and into your pee … the medicine is concentrated at the site of infection … You'll feel better within a few days for most infections. You can drink alcohol while taking nitrofurantoin.","accessed":"2026-08-27"},{"id":"nhs_nitro_how","url":"https://www.nhs.uk/medicines/nitrofurantoin/how-and-when-to-take-nitrofurantoin/","label":"NHS Medicines A-Z — How and when to take nitrofurantoin (reviewed 6 Jan 2026)","quote":"100mg, taken as slow release capsules, twice a day · 50mg, taken as standard tablets or capsules, 4 times a day · 100mg … 4 times a day, for severe infections … Take nitrofurantoin with or after a meal or snack.","accessed":"2026-08-27"},{"id":"nhs_nitro_who","url":"https://www.nhs.uk/medicines/nitrofurantoin/who-can-and-cannot-take-nitrofurantoin/","label":"NHS Medicines A-Z — Who can and cannot take nitrofurantoin (reviewed 6 Jan 2026)","quote":"tell your doctor if you have: porphyria … glucose-6-phosphate dehydrogenase (G6PD) deficiency … severe kidney disease … diabetes … a lung condition … problems with your liver … anaemia or vitamin B deficiency.","accessed":"2026-08-27"},{"id":"nhs_nitro_se","url":"https://www.nhs.uk/medicines/nitrofurantoin/side-effects-of-nitrofurantoin/","label":"NHS Medicines A-Z — Side effects of nitrofurantoin (reviewed 6 Jan 2026)","quote":"Serious side effects are rare and happen in less than 1 in 1,000 people … signs of lung problems … a sign of liver or gallbladder problems … pins and needles, tingling sensations, numbness or weakness.","accessed":"2026-08-27"},{"id":"nhs_nitro_int","url":"https://www.nhs.uk/medicines/nitrofurantoin/taking-nitrofurantoin-with-other-medicines-and-herbal-supplements/","label":"NHS Medicines A-Z — Taking nitrofurantoin with other medicines and herbal supplements (reviewed 6 Jan 2026)","quote":"indigestion remedies known as antacids, particularly those that contain magnesium … antibiotics known as quinolones … Typhoid vaccines given by mouth may not work properly if you're taking nitrofurantoin. It does not affect typhoid vaccines given by injection.","accessed":"2026-08-27"},{"id":"fda_macrobid","url":"https://api.fda.gov/drug/label.json?search=openfda.brand_name:%22MACROBID%22&limit=1","label":"FDA / openFDA drug label — Macrobid (nitrofurantoin monohydrate/macrocrystals) capsules, prescribing information (effective 9 Feb 2026)","quote":"Adults and Pediatric Patients Over 12 Years: One 100 mg capsule every 12 hours for seven days … Anuria, oliguria, or significant impairment of renal function (creatinine clearance under 60 mL per minute …) are contraindications … nausea (8%), headache (6%).","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."}