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Dextromethorphan oral

Updated 2 Feb 2023 | Cough suppressants


Oral formulations of dextromethorphan hydrobromide

Drugs List

  • BENYLIN DRY COUGHS 7.5mg/5ml syrup
  • dextromethorphan 20mg/15ml syrup
  • dextromethorphan 7.33mg lozenge
  • dextromethorphan 7.5mg/5ml oral solution
  • dextromethorphan 7.5mg/5ml oral solution sugar-free
  • ROBITUSSIN DRY COUGH linctus sugar-free
  • VICKS COUGH lozenge
  • VICKS VAPOSYRUP DRY COUGH 20mg/15ml syrup
  • Therapeutic Indications


    Cough (dry or painful)



    Individual brands may vary in their dosage recommendations and maximum daily dosage.

    15 - 20 mg dextromethorphan four times a day.

    Maximum suggested daily dose: 80 mg dextromethorphan.


    Individual brands may vary in their dosage recommendations and maximum daily dosage.

    15 - 20 mg dextromethorphan four times a day.

    Maximum suggested daily dose: 80 mg dextromethorphan.


    Individual brands may differ in their dosage recommendations for use in children.
    Not all brands are recommended to use in children under 12 years.

    Children 12 to 18 years
    15 - 20 mg dextromethorphan four times a day.

    Maximum suggested daily dose: 80 mg dextromethorphan.

    Children 6 - 12 years
    7.5mg dextromethorphan up to four times daily

    No more than 4 doses (30 mg) in 24 hours.


    Children under 6 years
    Predisposition to respiratory failure
    Productive cough
    Within 2 weeks of discontinuing MAOIs
    Acute asthma
    Hereditary fructose intolerance
    Respiratory failure
    Severe hepatic impairment

    Precautions and Warnings

    Children 6 to 12 years
    Diabetes mellitus
    Glucose-galactose malabsorption syndrome
    Hepatic impairment
    History of asthma

    Advise patient ability to drive or operate machinery may be impaired
    Advise patient dizziness may affect ability to drive or operate machinery
    Advise patient drowsiness may affect ability to drive or operate machinery
    Advise patient not to drive until they know how the medicine affects them
    Advise patient this medicine may be subject to driving restrictions
    Exclude chronic, persistent cough such as occurs with asthma or emphysema
    Not all available brands are licensed for use in children under 12 years
    Oral solution with maltitol unsuitable in hereditary fructose intolerance
    Presentations with sorbitol unsuitable in hereditary fructose intolerance
    Some formulations contain glucose
    Some formulations contain propylene glycol
    Some formulations contain sucrose
    Some formulations may contain alcohol
    Dose varies with brand
    Should not be taken with other cough or cold medicine
    Advise patient not to exceed stated dose
    Advise patient to consult a doctor if symptoms persist despite treatment

    MHRA/CHM advice (February 2009)
    Cough and cold remedies containing dextromethorphan should no longer be used in children under 6 as the balance of benefits and risk has not been shown to be favourable.

    Medicines to treat cough and colds in older children (6 to 12) can be considered after basic principles of best care have been tried.

    Products for children from 6 to 12 will continue to be available in pharmacies where advice can be given.

    MHRA/CHM advice (March 2008)
    Children should not be given more than one cough or cold preparation at a time because different brands may contain the same active ingredient; care should be taken to give the correct dose.

    Pregnancy and Lactation


    Use with caution during pregnancy.

    Dextromethorphan is widely used as a cough suppressant. It is considered safe for use during pregnancy, and can be given during all trimesters. However, higher doses for longer periods of time, or use near delivery may cause neonatal withdrawal and respiratory depression. No increased incidence of congenital malformations or human teratogenicity have been found. It is not known if it crosses the placenta, but this is likely, given its low molecular weight.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14-17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Use with caution during breastfeeding.

    Dextromethorphan has less sedative action than codeine. There is little data available on use during breastfeeding, but single doses are considered safe. Careful observation is required for repeated doses in case of somnolence. It is not known whether it is excreted in breast milk, but it is thought unlikely that transfer would occur in clinically significant amounts.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at

    Effects on Ability to Drive and Operate Machinery

    This class of medicine is in the list of drugs included in regulations under 5a of the Road Traffic Act 1988 (England and Wales). When prescribing this medicine: Advise patient the medicine can affect cognitive function and is likely to affect ability to drive. Advise patient not to drive until they know how the medicine affects them.


    Advise patient that if they have asthma, high fever, skin rash, sore throat or continuing headache, consult doctor before taking this medicine.

    It should not be used for more than 5 days without the advice of a doctor.

    Side Effects

    CNS excitation
    Gastro-intestinal symptoms
    Respiratory depression


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: March 2013

    Reference Sources

    British National Formulary, 64th Edition (2012) Pharmaceutical Press, London.

    BNF for Children (2012-2013) Pharmaceutical Press, London.

    Martindale: The Complete Drug Reference, 37th edition (2011) ed. Sweetman, S. Pharmaceutical Press, London.

    Summary of Product Characteristics: Benylin Dry Coughs (Non-Drowsy). Mc Neil Products Ltd. Revised March 2010.
    Summary of Product Characteristics: Robitussin Dry Cough Medicine. Pfizer Consumer Healthcare. Revised January 2012.
    Summary of Product Characteristics: Vicks Cough Syrup with Honey for Dry Coughs. Procter & Gamble. Revised April 2011.
    Summary of product characteristics: Vicks Cough Lozenges with Honey. Procter & Gamble. Revised March 2012.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 9th edition (2011) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia.

    Updated advice - Over-the-counter cough and cold medicines for young children. Medicines and Healthcare products Regulatory Agency. 27th March 2008.
    Available at:
    Last accessed: March 27, 2013

    Better medicines for children's coughs and colds. Medicines and Healthcare products Regulatory Agency. 28th February 2009.
    Available at:
    Last accessed: March 22, 2013 Government departments. Department for Transport. Publications. Drug driving and medicine: advice for healthcare professionals. Drug driving: Guidance for healthcare professionals on drug driving. Available at: Last accessed: 6 January 2015 New drug driving offence implications for medicines packaging. Medicines Regulatory News. 10 December 2013. Available at: Last accessed: 6 January 2015

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