{"ok":true,"entry":{"slug":"hydroxychloroquine","kind":"medication","name":"hydroxychloroquine","aliases":["Plaquenil"],"brands_sg":["Plaquenil","Haloxin","HCQS","Accoquin","Ovipla"],"class":"antimalarial / DMARD","tags":["other"],"use_for":"prescribed for lupus, rheumatoid arthritis and malaria","use_after":"nhs: several weeks to work; often 6 months or longer","use_duration":null,"take_with":"sg label: each dose with a meal or a glass of milk","pros":["sg label: either 200 mg or 400 mg a day in adults","healthhub: safe in pregnancy and breastfeeding","nhs: also used for sun-triggered skin conditions"],"cons":["nhs: stomach ache, nausea, headache, itchy rash","fda: retinal damage tracks cumulative dose","fda: qt prolongation and cardiomyopathy reported"],"dose_note":"the sg plaquenil label (sin12213p) sets the adult ceiling: 'This dose should not exceed 6.5mg/kg/day (calculated from ideal body weight and not actual body weight) and will be either 200mg or 400mg per day'; the us fda plaquenil label instead warns that 'Daily doses exceeding 5 mg/kg (actual weight) of hydroxychloroquine sulfate increase the incidence of retinopathy' — the two ceilings differ in both number and weight basis; as directed on the label or by your doctor","dosage":null,"ul_status":null,"sg_class":"prescription-only","cautions":["eye problems or maculopathy — nhs says it may not be suitable","g6pd deficiency — healthhub says to tell your doctor","psoriasis or porphyria — fda label says avoid","heart, liver, kidney or blood problems — nhs says tell your doctor"],"clashes":[{"src":["fda_plaquenil"],"note":"fda: not recommended together — added risk of ventricular arrhythmias","with":"drugs that prolong the qt interval or are arrhythmogenic"},{"src":["fda_plaquenil","nhs_hcq"],"note":"fda: serum digoxin may rise; the label says monitor levels","with":"digoxin"},{"src":["fda_plaquenil","nhs_hcq"],"note":"fda: absorption can drop; the label suggests a 4-hour gap · nhs lists indigestion medicines too","with":"antacids and kaolin"},{"src":["fda_plaquenil"],"note":"fda: hypoglycaemia risk rises; a dose reduction may be needed","with":"insulin and other diabetes medicines"},{"src":["fda_plaquenil"],"note":"fda: adverse reactions may be more frequent together","with":"methotrexate"}],"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":"Forensicclassification = 'Prescription Only' for all 6 hydroxychloroquine products on the register: SIN12213P PLAQUENIL TABLET 200 mg, SIN12669P and SIN11874P HALOXIN, SIN16632P HCQS, SIN16475P ACCOQUIN, SIN17243P OVIPLA — all oral tablets.","accessed":"2026-08-27"},{"id":"ndf_plaquenil","url":"https://www.ndf.gov.sg/about-drugs/product-information/sin12213p/","label":"MOH National Drug Formulary — PLAQUENIL TABLET 200 MG (White) [SIN12213P], SG product information (last updated 28 July 2026)","quote":"PRESCRIPTION ONLY MEDICINES … This dose should not exceed 6.5mg/kg/day (calculated from ideal body weight and not actual body weight) and will be either 200mg or 400mg per day … Each dose should be taken with a meal or glass of milk.","accessed":"2026-08-27"},{"id":"healthhub_hcq","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/hydroxychloroquine","label":"HealthHub (MOH Singapore / Pharmaceutical Society of Singapore) — Hydroxychloroquine medication information leaflet (reviewed 14 Nov 2025)","quote":"a disease modifying anti-rheumatic drug (DMARD) … Take this medication with or after food … safe to be taken during pregnancy and when breastfeeding … Inform your doctor if you have G6PD deficiency.","accessed":"2026-08-27"},{"id":"nhs_hcq","url":"https://www.nhs.uk/medicines/hydroxychloroquine/","label":"NHS Medicines A-Z — Hydroxychloroquine","quote":"It's only available with a prescription … swallow the tablets whole with a meal or glass of milk … It takes several weeks … it may not be suitable if you have liver, kidney, blood or heart problems, maculopathy.","accessed":"2026-08-27"},{"id":"fda_plaquenil","url":"https://api.fda.gov/drug/label.json?search=openfda.brand_name:%22PLAQUENIL%22&limit=1","label":"FDA / openFDA drug label — PLAQUENIL (hydroxychloroquine sulfate) tablets, prescribing information (effective 9 Apr 2026)","quote":"Daily doses exceeding 5 mg/kg (actual weight) of hydroxychloroquine sulfate increase the incidence of retinopathy … PLAQUENIL has a potential to prolong the QT interval … Avoid in patients with psoriasis … Avoid in patients with porphyria.","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."}