← All medications

Dextromethorphan

Medication antitussive cold & flurespiratory
Aka: DXM, Robitussin DM, Romilar
Brands seen in Singapore: Robitussin DM, Duro-Tuss DM, Beathorphan, Dexcophan, Strepsils Cough
Not medical advice. Check with your doctor or pharmacist before you start, stop or change the timing of anything you take.
How to use
What it’s for
Dry, persistent cough — dulls the urge to cough
When to take
Every 6–8 hours when needed · SG label caps 4 doses a day
Take with
With or without food · sipped slowly, undiluted (SG label)
Pros & cons
Pros
  • Pharmacy-only in SG — a pharmacist is involved
  • SG label sets a ceiling: max 4 doses per day
  • HealthHub: may be taken with or without food
Cons
  • Cochrane: no good evidence for or against otc cough
  • More adverse effects reported with dextromethorphan
  • Drowsiness or dizziness — driving care advised
Sources
  1. HealthHub (MOH Singapore) — Dextromethorphan, uses / administration / side effects / interactions (article last reviewed 9 Jul 2026) · read 2026-08-27
    what it says
    “Dextromethorphan is a cough suppressant that works by reducing the urge to cough … may be taken with or without food … Drowsiness or dizziness … monoamine oxidase inhibitors (MAOIs) … selective serotonin reuptake inhibitors (SSRIs) … serotonin norepinephrine reuptake inhibitors (SNRIs)”
  2. HealthHub (MOH Singapore) — Dextromethorphan, precautions and warning-signs sections (article last reviewed 9 Jul 2026) · read 2026-08-27
    what it says
    “You have a history of asthma or lung diseases … you are a smoker or have recently taken steps to quit smoking … Fever more than 38.6 oC … Cough lasting for longer than three to four weeks”
  3. MOH National Drug Formulary — DURO-TUSS DM Dry Cough Liquid 15MG/5ML [SIN17494P] (HSA-registered product record, indication and contraindications) · read 2026-08-27
    what it says
    “Forensic Classification: PHARMACY ONLY MEDICINES … DURO-TUSS DM Dry Cough Liquid is used to relieve persistent dry cough for adults and children … Do not take this medicine if … you are currently taking a prescription monoamine oxidase inhibitor (MAOI)”
  4. MOH National Drug Formulary — DURO-TUSS DM Dry Cough Liquid [SIN17494P], dosing table (the table is published as an image on the NDF product page) · read 2026-08-27
    what it says
    “Shake the bottle before use … Adults & Children over 12 years old — 10mL — Every 6 to 8 hours (Maximum 4 doses per day) … For oral use only. If cough persists, see your doctor or pharmacist.”
  5. MOH National Drug Formulary — ROBITUSSIN DM SYRUP [SIN12222P] (HSA-registered product record) · read 2026-08-27
    what it says
    “ROBITUSSIN DM SYRUP [SIN12222P] … DEXTROMETHORPHAN HBR - 30 MG/10 ML … GUAIPHENESIN - 200 MG/10 ML … Forensic Classification: PHARMACY ONLY MEDICINES … Licence Holder: HALEON SINGAPORE PTE. LTD.”
  6. HSA register of therapeutic products (data.gov.sg open data d_767279312753558cbf19d48344577084, datastore_search API) — dextromethorphan rows · read 2026-08-27
    what it says
    “Productname: BEATHORPHAN TABLETS 15 mg … Activeingredients: DEXTROMETHORPHAN HBr … Forensicclassification: Pharmacy Only … Productname: Strepsils Cough for Dry Cough Lozenges 5mg … Forensicclassification: Pharmacy Only”
  7. Cochrane Database of Systematic Reviews — Over-the-counter (OTC) medications for acute cough in children and adults in community settings (Smith, Schroeder, Fahey 2014; PMC7061814) · read 2026-08-27
    what it says
    “There is no good evidence for or against the effectiveness of OTC medicines in acute cough … higher numbers of adverse effects in participants taking preparations containing antihistamines and dextromethorphan … antitussives … were no more effective than placebo”
Report a correction View as JSON

Updated 2026-08-29. Every line above traces to a numbered source. Kozen-X is not a medical device and does not give medical advice. It lists what published sources have written down — nothing more. A pair not listed is unrecorded, not cleared. Before you start, stop or re-time anything, talk to your doctor or pharmacist.