{"ok":true,"entry":{"slug":"promethazine","kind":"medication","name":"promethazine","aliases":["Phenergan"],"brands_sg":["Xepagan","Promagen","Axcel Promethazine","Promezine","Votazine"],"class":"sedating antihistamine","tags":["allergy"],"use_for":"allergy symptoms, itch, nausea, motion sickness, sleep","use_after":"healthhub: when needed for symptoms, with or without food","use_duration":null,"take_with":"water · nhs: swallowed whole, and healthhub: no alcohol","pros":["healthhub: eases itch, runny nose and sneezing","nhs: also used for motion sickness and vertigo","sold at sg pharmacies without a prescription"],"cons":["healthhub: drowsiness, dizziness, dry mouth","fda: not for under-2s — fatal breathing risk","healthhub: constipation, trouble passing urine"],"dose_note":"the us fda label for promethazine hydrochloride tablets gives, for allergy, 'The average oral dose is 25 mg taken before retiring; however, 12.5 mg may be taken before meals and on retiring, if necessary' and, for motion sickness, 'The average adult dose is 25 mg taken twice daily'; the same label says the tablets 'are contraindicated for children under 2 years of age'. nhs lists adult doses ranging from 10 mg twice a day up to 25 mg four times a day for vertigo, which is the highest figure either source carries. sg-registered oral products are 5 mg/5 ml and 10 mg/5 ml syrups and a 25 mg tablet. in singapore the pharmacist or doctor sets the dose.","dosage":null,"ul_status":null,"sg_class":"pharmacy-only","cautions":["children under 2 — fda: contraindicated, risk of fatal respiratory depression","asthma or other lower-airway symptoms — fda: antihistamines are contraindicated","glaucoma, trouble passing urine, stomach ulcers or seizures (healthhub)","pregnancy or breastfeeding (healthhub)"],"clashes":[{"src":["hh_prom_food"],"food":true,"note":"healthhub: avoid alcoholic drinks as this may increase drowsiness","with":"alcohol"},{"src":["hh_prom_food","fda_prom_warn"],"note":"healthhub and fda: sedatives, opioids, tricyclics and tranquillisers amplify the impairment","with":"other sedating medicines"},{"src":["hh_prom_food"],"note":"healthhub: not to be taken with, or within 14 days of stopping, an maoi","with":"monoamine oxidase inhibitors (maois)"},{"src":["hh_prom_food"],"note":"healthhub: many otc medicines contain antihistamines — taking two risks overdosing","with":"other over-the-counter antihistamines"}],"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 locally)","quote":"17 of 18 registered promethazine products carry Forensicclassification 'Pharmacy Only' — XEPAGAN · PROMAGEN · AXCEL PROMETHAZINE-5 · PROMEZINE · VOTAZINE TABLET 25 mg; only SIN02707P DBL PROMETHAZINE INJECTION 50 mg/2 ml reads 'Prescription Only'. No Phenergan row exists.","accessed":"2026-08-27"},{"id":"hh_prom_uses","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/promethazine","label":"HealthHub (Pharmaceutical Society of Singapore) — Promethazine: what is this medication for","quote":"Promethazine belongs to a group of medicines known as antihistamines … Relief of itch in the eyes, nose or skin … Relief of runny nose and sneezing; Treat nausea and vomiting; Help you to fall asleep","accessed":"2026-08-27"},{"id":"hh_prom_admin","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/promethazine","label":"HealthHub — Promethazine: how should I take or use this medication","quote":"This medication may be taken with or without food. Take this medication when necessary to relieve your symptoms. Do not exceed the maximum dose as recommended by your healthcare professional.","accessed":"2026-08-27"},{"id":"hh_prom_precautions","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/promethazine","label":"HealthHub — Promethazine: what precautions should I take","quote":"You are pregnant, planning to become pregnant, or breastfeeding … Increased eye pressure (glaucoma); Difficulty in urinating … Stomach ulcers; Seizures; Kidney, liver, respiratory or thyroid diseases; High blood pressure or abnormal heart rhythm","accessed":"2026-08-27"},{"id":"hh_prom_se","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/promethazine","label":"HealthHub — Promethazine: common side effects","quote":"Drowsiness or feeling tired … Dizziness … Dry mouth … Constipation … Headache; Difficulty in passing urine or constipation","accessed":"2026-08-27"},{"id":"hh_prom_food","url":"https://www.healthhub.sg/medication-devices-and-treatment/medications/promethazine","label":"HealthHub — Promethazine: what food or medication should I avoid","quote":"Avoid alcoholic drinks as this may increase drowsiness. Avoid taking sedating medications … Do not take with or within 14 days of stopping monoamine oxidase inhibitors (MAOIs). Many over-the-counter medications contain antihistamines","accessed":"2026-08-27"},{"id":"nhs_prom_take","url":"https://www.nhs.uk/medicines/promethazine/how-and-when-to-take-promethazine/","label":"NHS Medicines A-Z — Promethazine (Phenergan): how to take it","quote":"Always take your promethazine tablets with a drink of water. Swallow them whole. Do not chew them. You can take promethazine with or without food.","accessed":"2026-08-27"},{"id":"nhs_prom_dose","url":"https://www.nhs.uk/medicines/promethazine/how-and-when-to-take-promethazine/","label":"NHS Medicines A-Z — Promethazine: dosage for hay fever or hives","quote":"For hay fever or hives the dose can vary from 10mg twice a day to 20mg 3 times a day or 25mg once or twice a day.","accessed":"2026-08-27"},{"id":"nhs_prom_vertigo","url":"https://www.nhs.uk/medicines/promethazine/how-and-when-to-take-promethazine/","label":"NHS Medicines A-Z — Promethazine: dosage for vertigo, and strengths","quote":"For vertigo the dose can vary from 25mg a day to 25mg 4 times a day. Promethazine tablets come in strengths of 10mg, 20mg or 25mg.","accessed":"2026-08-27"},{"id":"nhs_prom_motion","url":"https://www.nhs.uk/medicines/promethazine/how-and-when-to-take-promethazine/","label":"NHS Medicines A-Z — Promethazine: dosage for motion sickness","quote":"For preventing motion sickness you'll usually take 25mg the night before your journey … For treating motion sickness take 25mg as soon as possible and 25mg the same evening.","accessed":"2026-08-27"},{"id":"fda_prom_dose","url":"https://api.fda.gov/drug/label.json?search=openfda.generic_name:%22PROMETHAZINE+HYDROCHLORIDE%22+AND+openfda.route:%22ORAL%22&limit=1","label":"US FDA label for promethazine hydrochloride tablets USP, Dosage and Administration, via openFDA drug/label.json (effective 2024-10-30)","quote":"Allergy: The average oral dose is 25 mg taken before retiring; however, 12.5 mg may be taken before meals and on retiring, if necessary … Motion Sickness: The average adult dose is 25 mg taken twice daily.","accessed":"2026-08-27"},{"id":"fda_prom_ci","url":"https://api.fda.gov/drug/label.json?search=openfda.generic_name:%22PROMETHAZINE+HYDROCHLORIDE%22+AND+openfda.route:%22ORAL%22&limit=1","label":"US FDA label for promethazine hydrochloride tablets USP, Contraindications, via openFDA","quote":"Promethazine Hydrochloride Tablets, USP are contraindicated for use in pediatric patients less than two years of age … contraindicated in comatose state … Antihistamines are contraindicated for use in the treatment of lower respiratory tract symptoms including asthma.","accessed":"2026-08-27"},{"id":"fda_prom_warn","url":"https://api.fda.gov/drug/label.json?search=openfda.generic_name:%22PROMETHAZINE+HYDROCHLORIDE%22+AND+openfda.route:%22ORAL%22&limit=1","label":"US FDA label for promethazine hydrochloride tablets USP, Warnings (boxed warning text), via openFDA","quote":"Promethazine hydrochloride should not be used in pediatric patients less than 2 years of age because of the potential for fatal respiratory depression … The impairment may be amplified by concomitant use of other central-nervous-system depressants such as alcohol, sedatives/hypnotics","accessed":"2026-08-27"}],"brand_certs":null,"updated_at":"2026-08-29T16:16:29.426925+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."}