Pharmacy Guide
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
Pharmacy Guide
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
Rennie Gum 750mg Medicated Chewing Gum
⚠ This medicine appears to have been discontinued
The electronic medicines compendium (emc) no longer publishes a Summary of Product Characteristics for this product, which usually means it is no longer marketed in the UK. The patient leaflet below is kept for reference, but the product may not be available.
If you were prescribed this medicine, other products containing Calcium carbonate may still be available. Do not stop your treatment — ask your pharmacist or GP what to use instead.
What it is and what it is used for
FOR
Rennie 750mg medicated chewing gum contains isomalt and sorbitol This medicine contains 416 mg isomalt and 170 mg sorbitol in each chewing gum. Sorbitol is a source of fructose. If your doctor has told you that you (or your child) have an intolerance to some sugars or if you have been diagnosed with hereditary fructose intolerance (HFI), a rare genetic disorder in which a person cannot break down fructose, talk to your doctor before you (or your child) take or receive this medicine. This medicine contains less than 1 mmol sodium (23 mg) per chewing gum, that is to say essentially sodium-free.
What you need to know before you take it
E RENNIE® 750MG MEDICATED CHEWING GUM
Other medicines and Rennie 750mg medicated chewing gum
- Please tell your doctor or pharmacist if you are taking, or have recently taken any other medicines, including medicines obtained without prescription.
- If you are taking any of the following medicines speak to your doctor or pharmacist before taking this product because it can affect how these medicines work:
- Tetracyclines and quinolones (antibiotics)
- Bisphosphonates (used for osteoporosis)
- Dolutegravir (an anti-retroviral medicine used for the treatment of HIV infection)
- Levothyroxine (a thyroid hormone)
- Eltrombopag (used to increase the number of platelets)
- Digoxin (used for some heart conditions)
- Thiazide diuretics (water tablets to treat fluid retention and high blood pressure)
- Fluorides (for preventing dental caries)
- Phosphates (for clearing the bowel before a surgical procedure)
- Iron supplements
- Vitamin D-containing products To maximise the benefit of all medicines being used, take Rennie 750mg medicated chewing gum at least 4 hours before or after taking eltrombopag and 1 to 2 hours after taking any other medicines. Rennie 750mg medicated chewing gum with food and drink Avoid taking Rennie 750mg medicated chewing gum with large amounts of milk or dairy products. Pregnancy and breastfeeding Rennie 750mg medicated chewing gum can be used during pregnancy and breastfeeding if taken as instructed. As this product provides a substantial amount of calcium (300 mg per tablet) in addition to dietary calcium intake, pregnant women should strictly limit their use of this product to the maximum recommended daily dose and avoid concomitant, excessive intake of milk (1 litre contains up to 1.2 g calcium) and dairy products.
How to take it
RENNIE® 750MG MEDICATED CHEWING GUM Adults and children aged 12 years and over: Chew 1 or 2 pieces of gum as required, after meals and before bedtime, for a minimum of 15 minutes. Additional doses may be taken if the symptoms reoccur. Do not chew more than 10 gums per day. Do not swallow the remaining gum; however, dispose of it sensibly. Do not take more than the label tells you to. Children under 12 years: Not recommended. If symptoms persist after 14 days consult your pharmacist or doctor. Prolonged use should be avoided. If you take more Rennie 750mg medicated chewing gum than you should: Drink plenty of water and consult your doctor or pharmacist. Symptoms of an overdose include nausea and vomiting, tiredness, constipation and muscular weakness. If you have any questions on the use of this medicine, ask your doctor or pharmacist.
Possible side effects
Do not take Rennie 750mg medicated chewing gum if you:
- Have severe kidney disease
- Have high calcium in the urine or kidney stones
- Have high calcium or low phosphate levels in the blood
- Are allergic (hypersensitive) to any of the ingredients (listed in section 6)
Like all medicines, this medicine can cause side effects, although not everybody gets them. Side effects are unlikely at the recommended dose. If you experience the following side effects stop treatment immediately and seek medical advice. Rarely allergic reactions to ingredients have been reported, e.g. rashes, itching, difficulty in breathing and swelling of the face, mouth or throat and anaphylactic shock (anaphylactic shock is a severe sudden allergic reaction, symptoms of which are low blood pressure, shock, palpitations, difficulty in breathing, bronchospasm, skin reactions, abdominal pain or cramps, vomiting and diarrhoea). Long term use of high doses can cause high blood levels of calcium especially in people with kidney conditions. Symptoms of this may include nausea, vomiting, upset stomach, constipation, diarrhoea, tiredness, muscular weakness, headache, kidney problems and impaired sense of taste. In exceptional cases long term use of high doses can lead to milk-alkali syndrome which can cause high blood levels of calcium.
Warnings and precautions Please consult your doctor if you suffer frequently or need to use this medicine for more than 14 days in order to rule out more serious conditions. Please consult your doctor or pharmacist if you have mild or moderate kidney problems as regular blood tests should be carried out.
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.
Rennie 750mg medicated chewing gum is a sugar-free, mint-flavoured medicated chewing gum that gets to work within minutes to provide effective relief from heartburn, indigestion and acid reflux. Each piece of gum contains an antacid – calcium carbonate – that works quickly and powerfully to neutralise excess acid in the stomach.
How to store it
RENNIE® 750MG MEDICATED CHEWING GUM
Keep this medicine out of the sight and reach of children. Store below 30°C and store in the original package. Do not use this medicine after the expiry date which is stated on the carton and blister. The expiry date refers to the last day of that month. Do not throw away any unused medicines via waste water or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.
Contents of the pack and other information
What Rennie 750mg medicated chewing gum contains The active substance per chewing gum is 750 mg calcium carbonate. The other ingredients are acesulfame potassium, isomalt, menthol flavour, copovidone, sorbitol, sucralose, magnesium stearate, brilliant blue FCF colourant, peppermint extra flavour and chewing gum base. What Rennie 750mg medicated chewing gum looks like and contents of the pack Rennie 750mg medicated chewing gum are round bi-layered medicated chewing-gums, made of a speckled blue layer and a white layer embossed with "750". Rennie 750mg medicated chewing gum is available in packs of 10 or 20 pieces of gums. Not all pack sizes may be marketed. Marketing Authorisation Holder Bayer plc, 400 South Oak Way, Reading, RG2 6AD, UK. [email protected] Manufacturer Fertin Pharma A/S Dandyvej 19 7100 Vejle Denmark This leaflet was last revised in January 2025
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Frequently asked questions about Rennie Gum 750mg Medicated Chewing Gum
What is the active substance in Rennie Gum 750mg Medicated Chewing Gum?
The active substance in Rennie Gum 750mg Medicated Chewing Gum is calcium carbonate.
Where does this information come from?
This leaflet reproduces the patient information leaflet approved for Rennie Gum 750mg Medicated Chewing Gum, as published on the electronic medicines compendium (emc). The version printed inside your medicine’s packaging is the one that applies to you.
Can I get Rennie Gum 750mg Medicated Chewing Gum without a prescription?
Whether a medicine is available over the counter or on prescription only depends on its licence. Check the leaflet, or ask your pharmacist — they can tell you straight away.
About this leaflet
The text above reproduces the patient information leaflet approved for this medicine, restructured for easier reading.
- Source: electronic medicines compendium (emc), Datapharm
- Active substance: calcium carbonate
- Official document: view the original leaflet on emc →
⚕For healthcare professionals — Summary of Product Characteristics (SmPC)Full SmPC: dosage, interactions, contraindications, warnings+
4.1. Therapeutic indications
For the symptomatic relief of heartburn and acid related symptoms, such as indigestion, hyperacidity, flatulence, upset stomach, dyspepsia, biliousness, overindulgence in food and drink, indigestion during pregnancy, acid indigestion, nervous indigestion.
4.2. Posology and method of administration
Adults and children over 12 years:
One or two pieces of gum to be chewed as a single dose as required, usually after meals and before going to bed but also in between in case of heartburn or gastric pain.
The recommended time for chewing is 15 minutes and the remaining gum should not be swallowed.
A maximum daily dose of 8 g calcium carbonate, corresponding to 10 gums a day, must not be exceeded.
Children:
Not recommended for children under 12 years.
As with all antacids, if symptoms persist despite 14 days of continuous therapy, diagnostic measures are strongly recommended in order to rule out a more serious disease.
4.3. Contraindications
This product should not be administered to patients with:
• Hypersensitivity to any of the ingredients of the product
• Hypercalcaemia and/or conditions resulting in hypercalcaemia
• Nephrolithiasis due to calculi containing calcium deposits
• Severe renal insufficiency
• Hypophosphataemia
4.4. Special warnings and precautions for use
Prolonged use should be avoided.
• The stated dose should not be exceeded. If, after 14 days of treatment, symptoms persist or only partly disappear the patient should consult a doctor. As with other antacids, calcium carbonate may mask a malignancy in the stomach.
• Caution should be exercised in patients with mild to moderate impairment of renal function (see section 4.3 – contraindication in severe renal insufficiency). If this product is used in such patients, plasma calcium and phosphate levels should be regularly monitored.
• Long term uses at high doses can result in undesirable effects such as hypercalcaemia resulting in kidney damage or milk syndrome subsequent renal damage or milk-alkali syndrome, especially in patients with renal insufficiency.
• This product should not be used in patients with hypercalciuria (see also section 4.3). Prolonged use increases the risk of formation of renal calculi.
• This product should not be taken with large amounts of milk or dairy products.
• Due to the sorbitol and isomalt content, patients with rare hereditary fructose intolerance (HFI) should not take this medicine.
4.5. Interaction with other medicinal products and other forms of interaction
Changes in gastric acidity, such as that caused by the ingestion of antacids, can affect the rate and degree to which some concurrently administered medicines are absorbed.
• It has been shown that antacids which contain calcium may form complexes with certain substances e.g. antibiotics (such as tetracyclines and quinolones) and cardiac glycosides (e.g. digoxin), biphosphonates, dolutegravir, levothyroxine, and eltrombopag, resulting in decreased absorption. This should be borne in mind when concomitant administration is considered.
• Calcium salts can also impede the absorption of phosphates, fluorides and iron-containing products.
• Thiazide diuretics reduce the urinary excretion of calcium. Due to an increased risk of hypercalcaemia, serum calcium should be regularly monitored during concomitant use of thiazide diuretics.
• Vitamin D containing products
Therefore, it is preferable to take the antacid separately from other drugs, allowing at least 4 hours before or after taking eltrombopag and a 1-2 hour interval for all other drugs.
4.6. Fertility, pregnancy and lactation
Pregnancy
Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity.
No increased risks of congenital defects are anticipated, neither have they been observed after the long-term use of calcium carbonate during pregnancy.
This medicine can be used during pregnancy if taken as instructed.
The maximum recommended daily dose should not be exceeded and should not be taken for more than 2 weeks. If symptoms persist or only partly disappear after 2 weeks, medical advice should be sought.
In order to prevent calcium overload, pregnant women should avoid concomitant excessive intake of milk and dairy products 1 litre of milk contains up to 1.2 g elemental calcium).
Breastfeeding
Calcium carbonate is excreted in human milk, but at therapeutic doses of the product no effects on the breastfed newborns/infants are anticipated.
This medicine can be used during breastfeeding.
Fertility
There is no known evidence suggestive that at the recommended dose this medicine has adverse effects on human fertility.
4.7. Effects on ability to drive and use machines
No effects on ability to drive and use machines have been observed.
4.8. Undesirable effects
The listed adverse drug reactions are based on spontaneous reports, thus an organisation according to CIOMS III categories of frequency is not possible.
Immune System Disorders:
Hypersensitivity reactions have very rarely been reported. Clinical symptoms may include rash, urticaria, pruritus, angioedema, difficulty in breathing and anaphylaxis.
Metabolism and Nutrition Disorders:
Especially in patients with impaired renal function, prolonged use of high doses can result in hypercalcaemia and alkalosis.
Gastrointestinal Disorders:
Nausea, vomiting, stomach discomfort, constipation and diarrhoea may occur.
Musculoskeletal and Connective Tissue Disorders:
Muscular weakness may occur.
Undesirable effects occurring in the context of milk-alkali syndrome (see 4.9):
Gastrointestinal Disorders:
Ageusia may occur in the context of milk-alkali syndrome.
General Disorders and Administration Site Conditions:
Calcinosis and asthenia may occur in the context of milk-alkali syndrome.
Nervous System Disorders:
Headache may occur in the context of milk-alkali syndrome.
Renal and Urinary Disorders:
Azotemia may occur in the context of milk-alkali syndrome.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions 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.
4.9. Overdose
Especially in patients with impaired renal function, prolonged use of high doses of calcium carbonate can result in renal insufficiency, hypercalcaemia and alkalosis which may give rise to gastrointestinal symptoms (nausea, vomiting, constipation) and muscular weakness. In these cases, the intake of the product should be stopped and adequate fluid intake encouraged. In severe cases of overdosage (e.g. milk-alkali syndrome), a health care professional must be consulted because other measures of rehydration (e.g. infusions) might be necessary.
💬 Ask about this leaflet
Ask anything about Rennie Gum 750mg Medicated Chewing Gum. The assistant answers only from this leaflet — if the leaflet does not cover it, it will say so. It does not give medical advice.
Answers come from the patient leaflet published on the electronic medicines compendium (emc). They are not medical advice. Ask a pharmacist or your GP if you are unsure. For urgent help call NHS 111, or 999 in an emergency.
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- Calcium Carbonate 500 mg Chewable Tablets
- Calcium Carbonate 500mg Chewable Tablets (PL 43461/0190)
- Rennie Orange Flavour
- Setlers Antacid Chewable Tablets Peppermint Flavour
- Setlers Antacid Chewable Tablets Spearmint Flavour