If you are taking any of the following medicines speak to your doctor or pharmacist before taking Rennie Peppermint because it can affect how these medicines work. 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.

Rennie Spearmint - Patient Information Leaflet (PIL) - (emc)

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. Calcium salts reduce the absorption of fluorides and iron-containing products, and calcium salts and magnesium salts can hinder the absorption of phosphates. Long term uses at high doses can result in undesirable effects such as hypercalcaemia, hypermagnesaemia and milk-alkali syndrome, especially in patients with renal insufficiency. Rennie should not be used in patients with hypercalciuria (see also section 4.3). Prolonged use increases the risk of formation of renal calculi. If you are taking any of the following medicines speak to your doctor or pharmacist before taking Rennie Spearmint because it can affect how these medicines work.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. It has been shown that antacids which contain calcium or magnesium may form complexes with certain substances e.g. antibiotics (such as tetracyclines and quinolones), and cardiac glycosides (e.g. digoxin), bisphosphonates, dolutegravir, levothyroxine, and eltrombopag, resulting in decreased absorption. This should be borne in mind when concomitant administration is considered. Especially in patients with impaired renal function, prolonged use of high doses can result in hypermagnesaemia or hypercalcaemia and alkalosis which may give rise to gastric symptoms and muscular weakness (see below). Hypersensitivity reactions have very rarely been reported. Clinical symptoms may include rash, urticaria, pruritus, angioedema, difficulty in breathing and anaphylaxis.

Rennie Peppermint - Summary of Product Characteristics (SmPC Rennie Peppermint - Summary of Product Characteristics (SmPC

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. No increased risks of congenital defects have been observed after the use of this product during pregnancy. Caution should be exercised in patients with mild to moderate impairment of renal function (see section 4.3 – contraindication in severe renal insufficiency). If Rennie is used in such patients, plasma calcium, phosphate and magnesium levels should be regularly monitored. Calcium and magnesium are excreted in human milk, but at therapeutic doses of the product no effects on the breastfed newborns/infants are anticipated.Long term use of high doses can cause high blood levels of calcium and magnesium, 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. Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity. Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription.