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Alka-Seltzer XS

Active Ingredient:
acetylsalicylic acid, caffeine, paracetamol
About Medicine
The Patient Information Leaflet (PIL) is the leaflet included in the pack with a medicine.
Last updated on emc: 13 Jun 2023

Below is a text only representation of the Patient Information Leaflet (ePIL).

The text only version may be available in large print, Braille or audio CD. For further information call emc accessibility on {phone} 0800 198 5000. The product code(s) for this leaflet is: PL 00010/0510.

Alka-Seltzer XS


Alka-Seltzer. XS

Aspirin, Paracetamol, Caffeine

Read all of this leaflet carefully because it contains important information for you.

This medicine is available without prescription.

However, you still need to use Alka-Seltzer XS carefully to get the best results from it.

  • Keep this leaflet. You may need to read it again.
  • Ask your pharmacist if you need more information or advice.
  • You must contact a doctor if your symptoms worsen or do not improve after 3 days.
  • If you have any unusual effects after using this product, tell your doctor or pharmacist.


1. What is Alka-Seltzer XS and what is it used for?
2. Before you take Alka-Seltzer XS
3. How to take Alka-Seltzer XS
4. Possible side effects
5. How to store Alka-Seltzer XS
6. Further information


Alka-Seltzer XS are effervescent tablets which dissolve in water to give a sparkling solution. The active substances are: aspirin (acetylsalicylic acid), paracetamol and caffeine.

Aspirin belongs to a group of medicines known as non-steroidal anti-inflammatory drugs (NSAIDS).

Aspirin and paracetamol are both used for the treatment of pain and reduction of fever. Aspirin also has anti-inflammatory properties, whilst caffeine acts as mild stimulant.

Alka-Seltzer XS can be used for the:

  • Treatment of mild to moderate pain including headache, migraine, backache (including lumbago), nerve pain (neuralgia and sciatica), period pain, toothache and sore throat.
  • Symptomatic relief of colds and influenza.
  • Relief of rheumatic pain (arthritis), muscle tenderness and stiffness (including fibrositis), muscular aches and pains.
  • Effective reduction of high temperature.

DO NOT take Alka-Seltzer XS if you:
  • Are allergic (hypersensitive) to aspirin, paracetamol, caffeine or any of the ingredients (listed in Section 6, - Further Information)
  • Are allergic to any other pain relieving or anti-inflammatory medicines (eg NSAIDS or salicylates). For more information see section 4 ‘Possible Side Effects’.
  • Have a disorder which causes excessive bleeding such as haemophilia.
  • Have, or have had, a stomach or duodenal ulcer.
  • Are on a high dose of methotrexate (15mg per week or more). If you are not sure, check with your doctor. Also see ‘Using other medicines’.
  • Are pregnant or breast-feeding, unless advised by a doctor.

Speak to your doctor before taking Alka-Seltzer XS if you:
  • Suffer from tightness in the chest or asthma.
  • Have low uric acid excretion, which is commonly associated with gout.
  • Have a history of gastrointestinal disorders (regular stomach upsets).
  • Have kidney or liver problems .
  • Are about to have surgery. Before the operation tell the doctor or surgeon that you are taking aspirin.

If you are not sure whether any of the above apply to you, speak to a doctor or pharmacist before taking Alka-Seltzer XS.

Important information about some of the ingredients:

This medicine contains 472 mg sodium (main component of cooking/table salt) in each tablet.

This is equivalent to 23.6% of the recommended maximum daily dietary intake of sodium for an adult.

Use in children:

Aspirin can cause Reye’s syndrome when it is given to children. Reye’s syndrome is a very rare disease, which can be fatal. For this reason aspirin should not be given to children under 16 years, unless your doctor tells you to.

Using other medicines:

Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription.

Aspirin can affect the way in which some medicines work. These medicines include:

  • Medication to prevent blood clotting (eg warfarin, heparin, ticlopidine).
  • Medication to treat heart problems or to lower blood pressure (eg ACE inhibitors or digoxin).
  • Medication to treat gout.
  • Diuretics (to treat water retention).
  • Medication to treat epilepsy (eg sodium valproate, phenytoin).
  • Medication to lower blood sugar if you are diabetic.
  • Methotrexate (to treat psoriasis, rheumatoid arthritis, Crohn’s disease and some types of cancer).
  • Any pain-relieving or anti-inflammatory medicines.
  • Medication containing corticosteroids.

Paracetamol can affect the way in which some medicines work. These medicines include:

  • Metoclopramide (to treat nausea and vomiting).
  • Domperidone (to treat nausea, vomiting, indigestion).
  • Colestyramine (to treat high cholesterol).

Do not take other products containing paracetamol whilst taking this product.

Taking with food and drink:

Avoid taking alcohol while taking Alka-Seltzer XS.

Pregnancy and breast-feeding:

Do not take Alka-Seltzer XS if you are pregnant, breast-feeding or trying for a baby unless directed by your doctor. Aspirin can prolong labour and affect blood clotting in the mother or baby.

Always ask your doctor or pharmacist for advice before taking any medicine.


Follow the directions below closely. You should ask your doctor or pharmacist if you are unsure how to use this medicine.

Alka-Seltzer XS tablets must always be dissolved in water before use.

Adults and children over 16:

Two tablets dissolved in half a glass (100ml) of water may be taken every 4 hours as required. You should not take more than 8 tablets in 24 hours.

Not recommended in children under 16.

Make sure you follow the dosage instructions and do not take more than the stated dose.

Do not take Alka-Seltzer XS for more than 3 days in a row. If you do not get better, talk to your doctor.

If you take more Alka-Seltzer XS than you should:

Talk to a doctor at once if you take too much of this medicine even if you feel well. This is because too much paracetamol can cause delayed, serious liver damage.


Like all medicines Alka-Seltzer XS can cause side effects although not everybody gets them.

If you experience any of the following side effects, stop taking Alka-Seltzer XS and go to your nearest Accident and Emergency Department or doctor immediately:

  • An allergic reaction. Signs of allergic reaction may include: difficulty in breathing or swallowing, swelling of the face, lips, throat or tongue, skin rashes, large or itchy wheals on the skin, attacks of sneezing, runny nose and itching eyes or water retention.
  • Stomach bleeding, which may result in black or tarry stools.
  • Nausea or vomiting.
  • Dizziness or ringing in the ears.
  • Diarrhoea.
  • Increased bleeding/blood thinning (if you cut or injure yourself).
  • An asthma attack if you are asthmatic and sensitive to aspirin.
  • Changes in normal liver activity in blood tests (very rare).

Very rare cases of serious skin reactions have been reported.

If you have unusual stomach pains or react badly to this medicine in any other way, stop taking Alka-Seltzer XS and tell your doctor or pharmacist immediately.

Reporting of side effects

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at:

By reporting side effects you can help provide more information on the safety of this medicine.


Keep out of the sight and reach of children.

Do not store above 25 °C. Store in a dry place. This product should be stored in its original carton.

This product is packaged in pouches containing 1 or 2 tablets. If the pouch is damaged or if a tablet is powdery or discoloured, do not use the tablet.

Do not use Alka-Seltzer XS after the expiry date which is stated on the carton and on the foil pouch.

The expiry date refers to the last day of that month.

Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. These measures will help to protect the environment.

What Alka-Seltzer XS contains:

The active substances are aspirin (acetylsalicylic acid) (267mg per tablet), paracetamol (133mg per tablet) and caffeine (40mg per tablet).

The other ingredients are sodium hydrogen carbonate and citric acid.

See section 2 ‘Important information about some of the ingredients’ for sodium advice.

What Alka-Seltzer XS looks like and contents of the pack:

Alka-Seltzer XS comes in cartons containing 2, 10, 12, 20 or 30 white effervescent tablets packaged in foil pouches. Not all pack sizes may be marketed.

Marketing Authorisation Holder:
Bayer plc
400 South Oak Way

Bayer Bitterfeld GmbH
OT Greppin
Salegaster Chaussee 1
06803 Bitterfeld-Wolfen

This leaflet was last revised in November 2022.

Alka-Seltzer® is a registered trademark.


Bayer plc
Company image
400 South Oak Way, Reading, Berkshire, RG2 6AD
+44 (0)118 206 3000
Medical Information e-mail
[email protected]