sodium content in prescribed medication

Last edited 04/2019 and last reviewed 03/2022

  • in the UK, daily target average salt intakes are 6g for adults and children aged eleven and over, 5g for those aged seven to ten years, 3g for those aged four to six years and 2g for those aged one to three years (1)
    • infants aged seven to twelve months should receive no more than 1g salt daily and infants of six months and under should receive less than 1g daily
    • 6g of salt corresponds to approximately 2.4g or 100mmol of sodium
      • the maximum daily dose of some medicines may contain more sodium than this. For example, most soluble paracetamol and co-codamol preparations contain more than 16mmol of sodium per tablet
        • thus a person taking the maximum dose of eight tablets per day would exceed their recommended daily sodium allowance without accounting for their dietary intake (1)

European Commission guidelines specify the information that must be included in the package leaflet (2)

  • requirement applies to all medicines licensed for use in the UK (3)
    • for medicines containing less than 1mmol sodium per dose
      • this medicine contains less than 1mmol sodium (23mg) per, that is to say essentially 'sodium-free'

    • for medicines containing 1mmol sodium or more per dose
      • this medicine contains Xmg sodium (main component of cooking/table salt) in each . This is equivalent to Y% of the recommended maximum daily dietary intake of sodium for an adult

    • for medicines containing 17mmol sodium or more in the maximum daily dose - 'Talk to your doctor if you need or more daily for a prolonged period, especially if you have been advised to follow a low salt (sodium) diet' This applies only to products for which the labelled posology allows the product to be taken on a daily basis for more than one month or repeated use for more than 2 days every week. 17mmol is approximately 20% of the World Health Organisation adult recommended maximum daily dietary intake of 2g sodium and is considered to represent 'high' sodium. However, it is noted that there is no evidence to suggest the level of sodium that is acceptable and it is expected to vary between individuals

It is noted that (1):

  • anybody who has a condition associated with sodium retention, such as hypertension, heart failure or renal impairment, or is following a salt-restricted diet, should avoid regular use of effervescent or soluble analgesics, indigestion remedies or other medicines containing high levels of sodium
    • suitable alternative antacid preparations are listed as 'low in sodium' in the BNF
  • the amount of sodium in non-soluble analgesics is insignificant. Orodispersible preparations do not contain significant amounts of sodium

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