Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity. Hypersensitivity reactions have very rarely been reported. Clinical symptoms may include rash, urticaria, pruritus, angioedema, difficulty in breathing and anaphylaxis. Calcium salts can also impede the absorption of phosphates, fluorides and iron-containing products. 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 and phosphate levels should be regularly monitored. Long term uses at high doses can result in undesirable effects such as hypercalcaemia and milk-alkali syndrome, especially in patients with renal insufficiency.

Taking Rennie Dual Action Tablets with milk or dairy products over a long period of time may cause milk alkali syndrome, which can cause high blood levels of calcium. Specific symptoms of milk alkali syndrome may include impaired sense of taste, headache, kidney problems, fatigue and lumps under the skin. Calcium carbonate is excreted in human milk, but at therapeutic doses of the product no effects on the breastfed newborns/infants are anticipated.Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription. No increased risks of congenital defects have been observed after the use of this product during pregnancy.

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. Patients with rare hereditary problems of fructose intolerance, glucose- galactose malabsorption or sucrase-isomaltase insufficiency should not take this medicine. 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. 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.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 taking antibiotics (tetracyclines, quinolones), cardiac glycosides (digoxin, digitoxin), bisphosphonates (used for the treatment of osteoporosis), dolutegravir (an anti-retroviral medicine used for the treatment of HIV infection), levothyroxine (a thyroid hormone), eltrombopag (a medicine used to increase the number of platelets) or other prescribed medicines (e.g. fluorides, phosphate, iron containing products) speak to your doctor before taking Rennie Dual Action Tablets because it can affect how these medicines work. To maximise the benefit of all medicines being used, take Rennie Dual Action Tablets 1 to 2 hours after taking any other medicines.

Adults and children over 12 only: 2 tablets to be chewed, preferably 1 hour after meals and before bedtime. For heartburn an extra 2 tablets may be taken between these times. Do not take more than 12 tablets in 24 hours. Rennie Dual Action Tablets can be used during pregnancy and breast feeding if taken as instructed above.Especially in patients with impaired renal function, prolonged use of high doses can result in hypercalcaemia and alkalosis. Long term use of high doses can cause high blood levels of calcium and magnesium, especially in people with kidney conditions. This can cause nausea and vomiting, upset stomach, diarrhoea, tiredness, muscular weakness, confusion, increased urine production, increased thirst and dehydration. 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. If you take more Rennie Dual Action Tablets than you should: Drink plenty of water and consult your doctor or pharmacist. Symptoms of an overdose include nausea and vomiting, constipation, tiredness, increased urine production, increased thirst, dehydration and abnormal muscular weakness. 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.