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Citric acid with magnesium carbonate oral

Updated 2 Feb 2023 | Colonic evacuation


Oral formulations containing heavy magnesium carbonate and anhydrous citric acid

Drugs List

  • CITRAMAG powder
  • citric acid 17.79g/sachet and magnesium carbonate 11.57g/sachet powder sugar-free
  • Therapeutic Indications


    Preparation for radiological, endoscopic and surgical procedures on colon



    Two sachets (dissolved in water) should be taken on the day before the procedure at the appointed times:

    The first at 08:00hrs and the second between 14:00hrs and 16:00hrs (see Administration).

    The dose should be reduced for very ill, thin or elderly patients who may not be able to tolerate vigorous purgation very well.


    Dose may need to be reduced in very thin, frail or debilitated elderly patients.
    In such cases, it is recommended that half the adult dose may be sufficient.


    Children aged 10 years or over
    Half the adult dose
    To be taken on the day prior to the procedure at the same times specified for adults

    Children aged 5 to 9 years
    One third the adult dose
    To be taken on the day prior to the procedure at the same times specified for adults

    Patients with Renal Impairment

    Should be used with caution in mild and moderate renal impairment, due to a risk of toxic hypermagnesaemia. No specific dosage amendment is recommended.

    Magnesium citrate is principally excreted via the kidneys and should be accompanied by a high intake of water during the day of treatment.

    Patients with Hepatic Impairment

    All magnesium salts should be avoided in hepatic coma if there is a risk of renal failure.


    For oral administration.

    The contents of each sachet should be dissolved in 200ml of hot water half an hour before taking and allowed to cool.


    Children under 5 years
    Delayed gastric emptying
    Gastrointestinal obstruction
    Gastrointestinal perforation
    Gastrointestinal ulcer
    Inflammatory bowel disease
    Paralytic ileus
    Renal impairment - glomerular filtration rate below 30ml/minute/1.73m sq
    Renal impairment associated with hepatic coma
    Toxic colitis
    Toxic megacolon

    Precautions and Warnings

    Disorder of fluid balance
    Impaired consciousness
    Predisposition to aspiration or regurgitation
    Electrolyte imbalance
    Reflux oesophagitis
    Renal impairment
    Ulcerative colitis

    Observe patients prone to aspiration/regurgitation during administration
    Correct hypovolaemia prior to administration
    Maintain adequate hydration during therapy
    Oral medications given < 1 hr before treatment may be rendered ineffective
    Measure renal function where risk of fluid or electrolyte imbalance
    Monitor serum magnesium regularly in patients with renal impairment
    Reduce dose in debilitated patients
    Reduce dose in elderly
    Advise patient of appropriate fluid / dietary intake prior to procedure
    Advise patient of the vigorous nature of the purgation

    Caution is advised when the bowel cleansing treatment is used in patients taking ACE inhibitors, angiotensin-II receptor antagonists and NSAIDs due to the risk of dehydration and hypovolaemia. Consider withholding these drugs on the day and for up to 72 hours after the procedure. Caution is also advised in patients already receiving diuretics which may be associated with hypokalaemia. Consider withholding diuretics on the day that the bowel cleansing preparation is given.

    Pregnancy and Lactation


    Use with caution in pregnancy. No data available to confirm safety.

    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 to 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 in breast feeding. No data available to confirm safety.

    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


    Advise patient to follow the dosage instructions and suggested times of administration carefully.

    Side Effects

    Prolongation of QT interval
    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: August 2014

    Reference Sources

    Joint Formulary Committee. British National Formulary(online) London: BMJ Group and Pharmaceutical Press [Accessed on 21 August 2014].

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

    Paediatric Formulary Committee. BNF for Children (online) London: BMJ Group, Pharmaceutical Press, and RCPCH Publications [Accessed on 21 August 2014].

    Summary of Product Characteristics: Citramag. Sanochemia Diagnostics UK Ltd. Revised November 2012

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