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Aspirin with sodium bicarbonate and citric acid

Updated 2 Feb 2023 | Aspirin


Effervescent tablets containing 324mg acetylsalicylic acid, 965mg citric acid and 1744mg sodium hydrogen carbonate.
The active ingredients in water become sodium citrate 1296mg, sodium acetylsalicylate 364mg and sodium hydrogen carbonate 328mg.

Drugs List

  • ALKA-SELTZER effervescent tablet
  • Therapeutic Indications


    Symptomatic relief of headache and dyspepsia, sprains, strains, rheumatic pain, sciatica, lumbago, fibrositis, muscular aches and pains, joint swelling and stiffness.

    For the treatment of mild to moderate pain including migraine, neuralgia, toothache, sore throat, period pains, and general aches and pains.

    Symptomatic relief of influenza, pyrexia, and feverish colds.



    Two tablets dissolved in water. This dose may be repeated every 4 hours, as required, to a maximum of 4 doses in any 24 hour period.

    Treatment should not be continued for more than 3 days without consulting a physician.


    (See - Dosage - Adults)


    Children under 16 years
    Contraindicated in children under 16 years, unless specifically prescribed for an indication such as Kawasaki's disease.

    Children over 16 years
    (See - Dosage - Adults )

    Patients with Renal Impairment

    Use with caution in patients with renal impairment.

    Patients with Hepatic Impairment

    Use with caution in patients with hepatic impairment.


    For oral administration.

    The effervescent tablets must always be dissolved in a glass of water prior to administration. The tablets dissolve more quickly in warm water.


    Active peptic ulcer

    History of peptic ulceration

    Haemorrhagic disease such as haemophilia

    Third trimester of pregnancy (see Pregnancy)

    Children under 16 years

    Precautions and Warnings

    Aspirin can precipitate bronchospasm and induce asthma attacks or other hypersensitivity reactions in susceptible individuals.

    Renal impairment

    Hepatic impairment

    If symptoms persist for more than 3 days, patients should be advised to contact their doctor, long term, chronic use should be avoided.

    There is a possible association between aspirin and Reye's syndrome in children under 16 years, and so aspirin should only be administered to children under 16 when specifically indicated.

    Pregnancy - first and second trimester (see Pregnancy)

    Breastfeeding (see Lactation)

    Do not give aspirin to children under 16 years unless medically indicated (e.g. for Kawasaki syndrome)

    Sodium restricted diet

    Any degree of worsening of asthma may be related to the ingestion of NSAIDs, either prescribed or (in the case of ibuprofen and others) purchased over the counter.

    Pregnancy and Lactation


    This medication should be used with extreme caution during the first and second trimester. This product should not be used during the third trimester. Aspirin has been used for many years during pregnancy, however, the safety of aspirin in pregnancy is still under question. Aspirin crosses the placenta and can accumulate in the foetus due to slow elimination by the foetus. Briggs (2008) states that aspirin used near term may prolong gestation and labour, and increase the risk of haemorrhage during delivery. Premature closure of the ductus arteriosus may occur if aspirin is used late in the pregnancy, with the possibility of the associated complication of persistent pulmonary hypertension of the newborn. Therefore, this product is contraindicated during the third trimester and extreme caution is advised if this product is to be used during the first and second trimesters.

    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 at ( ) or if this is unavailable at the backup site ( ).

    Licensed in pregnancy? - No

    Recommended for use in pregnancy? - No

    Known human teratogen? - Unknown

    Crosses placenta? - Aspirin is known to cross the placenta.

    Effects on foetus - There is still a question about the safety of aspirin during the pregnancy, however, use near term is associate with premature closure of the ductus arteriosus, persistent pulmonary hypertension of the newborn, and haemorrhage.

    Pregnancy-specific adverse effects on the mother - Aspirin is associated with prolonged gestation and labour, and haemorrhage.


    The medication is contraindicated while breastfeeding. Aspirin in excreted in breast milk in small amounts, although aspirin clearance from breast milk is slower than that from plasma. High doses of aspirin present a potential risk to the infants platelet function. There is a possible association between aspirin and Reye's syndrome when given to children. Reye's syndrome is a very rare disease, which affects the brain and liver, and can be fatal. Schaefer (2007) and Lee (2000) both suggest that aspirin should not be used chronically in nursing mothers.

    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

    Drug excreted in breast milk? - Yes.

    Considered suitable or recommended by manufacturer? - No

    UK Drugs in Lactation Advisory Service Classification - Aspirin is classified as - insufficient information relating to breast-feeding available to allow classification as a safe drug.

    Drug substance licensed in infants? - No

    Side Effects

    Gastro-intestinal symptoms
    Gastro-intestinal haemorrhage
    Gastro-intestinal ulceration
    Gastro-intestinal perforation
    Hypersensitivity reactions
    Liver function disturbances
    Skin reactions
    Increased bleeding tendency


    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 ( ).

    The MHRA have produced 'generic' overdose sections for the top ten drugs for which the NPIS received the greatest number of queries about management of overdose in 2002. This information is attached below:

    Salicylate poisoning is usually associated with plasma concentrations >350 mg/L (2.5 mmol/L). Most adult deaths occur in patients whose concentrations exceed 700 mg/L (95.1 mmol/L). Single doses less than 100 mg/kg are unlikely to cause serious poisoning.

    Signs and Symptoms

    Common features include vomiting, dehydration, tinnitus, vertigo, deafness, sweating, warm extremities with bounding pulses, increased respiratory rate and hyperventilation. Some degree of acid-base disturbance is present in most cases.

    A mixed respiratory alkalosis and metabolic acidosis with normal or high arterial pH (normal or reduced hydrogen ion concentration) is usual in adults and children over the age of four years. In children aged four years or less, a dominant metabolic acidosis with low arterial pH (raised hydrogen ion concentration) is common. Acidosis may increase salicylate transfer across the blood brain barrier.

    Uncommon features include haematemesis, hyperpyrexia, hypoglycaemia, hypokalaemia, thrombocytopaenia, increased INR/PTR, intravascular coagulation, renal failure and non-cardiac pulmonary oedema.

    Central nervous system features including confusion, disorientation, coma and convulsions are less common in adults than in children.


    Give activated charcoal if an adult presents within one hour of ingestion of more than 250 mg/kg. The plasma salicylate concentration should be measured, although the severity of poisoning cannot be determined from this alone and the clinical and biochemical features must be taken into account. Elimination is increased by urinary alkalinisation, which is achieved by the administration of 1.26% sodium bicarbonate. The urine pH should be monitored. Correct metabolic acidosis with intravenous 8.4% sodium bicarbonate (first check serum potassium). Forced diuresis should not be used since it does not enhance salicylate excretion and may cause pulmonary oedema.

    Haemodialysis is the treatment of choice for severe poisoning and should be considered in patients with plasma salicylate concentrations >700 mg/L (5.1 mmol/L), or lower concentrations associated with severe clinical or metabolic features. Patients under ten years or over 70 have increased risk of salicylate toxicity and may require dialysis at an earlier stage

    Reference Sources

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 2nd edition (2007) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 8th edition (2008) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia

    Medications and Mother's Milk, 13th edition (2008) Hale, T.W. Hale Publishing, Amarillo, Texas.

    Summary of Product Characteristics, Alka-Seltzer Original, Bayer plc, Revised February 2010

    Therapeutics in Pregnancy and Lactation (2000) Lee, A., Inch, S. and Finnigan, D. Radcliffe Medical Press, Abingdon.

    US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
    Available at:
    Aspirin Last revised: December 27, 2007.
    Last accessed: October 20, 2010.

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