Patient leaflet - Resonium A
1. What Resonium A is and what it is used for
Resonium A contains a medicine called sodium polystyrene sulfonate. This belongs to a group of medicines called ‘ion exchange resins’. Resonium A is used to treat something called ‘hyperkalaemia’. This is when there is too much potassium in your blood. It works by removing this extra potassium to bring your levels back to normal. It is often given to people who have kidney problems and people on dialysis.
2. What you need to know before you use Resonium A
Do not use Resonium A if:
× You are allergic to sodium polystyrene sulfonate or any of the other ingredients in this medicine (listed in section 6).
Signs of an allergic reaction include: a rash, swallowing or breathing problems
, swelling of your lips, face, throat, or tongue
× You have been told that you have a low level of potassium in your blood × Your gut is partially or completely blocked (obstructive bowel disease) × You are taking a sweetener called sorbitol (a «sugar-free» sweetener used to sweeten food). This is because taking sorbitol and Resonium A at the same time can cause narrowing of the gut wall (gastrointestinal stenosis) and reduced blood flow to the gut wall (intestinal ischemia) causing severe damage to your gut (necrosis and perforation). You must not take any sorbitol whilst
recommended maximum daily dietary intake of sodium for an adult. Talk to your doctor or pharmacist if you need 15g or more daily for a prolonged period, especially if you have been advised to follow a low salt (sodium) diet.
3. How to use Resonium A
Your doctor or nurse will normally give you this medicine. Always use this medicine exactly as your doctor has told you. Check with your doctor if you are not sure.
The recommended dose is:
- The dose will depend on the results of blood tests
- For children the dose is also worked out according to how much the child weighs
Using the medicine
- Resonium A can be given by mouth or put into the back passage (rectum)
- If given by mouth the powder can be swallowed with a little water or be made into a paste with something sweet, such as jam or honey
- It should not be mixed with fruit juice, this will stop the medicine working properly
- If given by mouth, it is important to sit up while using the medicine so that you do not breathe in any powder into your lungs
If given by the back passage you should try to keep the medicine in your back passage for at least 9 hours. Then it needs to be thoroughly washed out
How much is normally given:
Adults (including the elderly)
By mouth
- The usual dose is 15g (one spoonful) three or four times a day
- Use at least 3 hours before or 3 hours after other oral medicines you may be taking. If you suffer from gastroparesis (a condition where your stomach can’t empty itself in the normal way), leave at least 6 hours before or after taking other oral medicines.
Into the back passage
- The usual dose is 30g (two spoonfuls) once a day
In some cases, the medicine may be given both by mouth and into the back passage. This is where your potassium levels need to be lowered more quickly.
Children
If your child cannot take the medicine by mouth, it may be given into the back passage.
- The daily dose is 1g for each kilogram of bodyweight
- Once the medicine has started working the dose may be lowered to 0.5g daily for each kilogram of bodyweight
New-born babies
Resonium A is only given into the back passage
- The daily dose is between 0.5g and 1g for each kilogram of bodyweight It is important to give the right dose for children and babies. If too much is given, children and babies could get serious constipation.
If you use more Resonium A than you should
It is unlikely that your doctor or nurse will give you too much medicine. Your doctor and nurse will be checking your progress, and checking the medicine that you are given. Ask them if you are not sure why you are getting a dose of medicine.
If you are given too much Resonium A the following effects may happen:
- Feeling irritable or confused
- Being unable to concentrate
- Muscle weakness and poor reflexes leading to paralysis
- Breathing problems
- Faster or pounding heartbeat
- Muscle cramps
If you forget to use Resonium A
Your doctor or nurse will give instructions about when to have your medicine. It is unlikely that a dose will be missed. If you think that you may have missed a dose, talk to your doctor or nurse.
If you stop using Resonium A
Keep using Resonium A until your doctor tells you to stop. If you stop using Resonium A, your illness may come back.
Blood Tests
Your doctor may do regular blood tests while you are using this medicine. This is to check the levels of salts (potassium, sodium, calcium and magnesium) in your blood.
If you have any further questions on the use of this product, ask your doctor, nurse or pharmacist.
4. Possible side effects
Like all medicines, this medicine can cause side effects, although not everybody gets them.
Tell a doctor or nurse straight away if you notice any of the following serious side effects:
- You have an allergic reaction. The signs may include: a rash, swallowing or breathing problems, swelling of your lips, face, throat or tongue
- Severe stomach pain, rectal pain
- Bloating, severe constipation
- Severe nausea and vomiting
- Black, bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds.
- Blood in your sick (vomit)
Talk to your doctor or nurse if you get any of the following side effects:
- Feeling tired, confused, having muscle weakness, cramps or a change in heart rate. These may be due to having low levels of potassium in your body
- Feeling jittery, having fits or muscle cramps. This may be due to low levels of calcium or magnesium in your body
- High blood pressure, kidney problems, heart problems or swelling in your limbs. This may be due to high levels of sodium in your body
- Stomach upset, pain in your gut, narrowing or blockage of the gut
- Reduced blood flow to the gut wall causing severe abdominal (tummy) pain, or collapse
- Loss of appetite
- Feeling sick, being sick, constipation or diarrhoea
- Feeling short of breath or coughing. This could be the first sign of a serious chest infection. This can be caused by accidentally breathing in this medicine
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:
www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
By reporting side effects you can help provide more information on the safety of this medicine.
5. How to store Resonium A
This medicine will be kept by your doctor or pharmacist in a safe place where children cannot see or reach it. Store in a dry place.
Do not use Resonium A after the expiry date which is stated on the container. The expiry date refers to the last date of that month.
This medicine must be used within 1 month of opening.
Do not throw away medicines via wastewater or household waste.
Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.
6. Contents of the pack and other information
What Resonium A contains
- 99.934% w/w of the active substance, sodium polystyrene sulfonate
- The other ingredients are saccharin, vanillin and sodium.
What Resonium A looks like and contents of the pack
Resonium® A is a buff coloured powder. It is supplied in containers of 454g with a 15g scoop.
Marketing Authorisation Holder and Manufacturer
Marketing Authorisation Holder
Sanofi, 410 Thames Valley Park Drive, Reading, Berkshire, RG6 1PT, UK Tel: 0800 035 2525
email: uk-medicalinformation@sanofi.com
Manufacturer
Astrea Amilly, 196 avenue du Maréchal Juin, 45200 Amilly, France This leaflet does not contain all the information about your medicine. If you have any questions or are not sure about anything, ask your doctor, nurse or pharmacist.
This leaflet was last revised in 09/2026
© Sanofi , 1989 – 2026