Calcium carbonate (Calcichew)

How does it work?

Calcichew tablets contain the active ingredient calcium carbonate, which is a calcium salt used mainly to supplement calcium in the diet.

Calcium is an essential mineral needed for many purposes in the body, including the formation of strong bones. Calcium requirements are raised in the years following the menopause, and when dietary intake of calcium is low. Calcium supplements have been shown to help prevent bone loss.

Calcium is found in milk and dairy products, as well as spinach, nuts and sardines. Usually, calcium requirements are met from the diet. However, there are times when the amount of calcium required is increased, such as during growth, pregnancy, when breastfeeding or with advancing age. When there is insufficient calcium in the diet to meet the body's needs, supplements are needed, otherwise calcium deficiency can occur.

Calcium supplements are useful in osteoporosis; a calcium intake that is twice the recommended daily allowance (RDA) slows the rate of bone loss and reduces the risk of fractures.

Calcium carbonate is also used in people with kidney failure to bind to phosphate consumed in the diet. This is because in kidney failure the kidneys are less able to remove phosphate from the blood and it builds up in the body, often causing itching of the skin. High levels of phosphate also lead to a drop in the amount of calcium in the body, and as a result the body starts removing calcium from the bones. This can cause renal bone disease. Calcium carbonate is used as a phosphate binder in kidney failure to reduce the amount of phosphate absorbed from the gut. It therefore helps prevent these problems.

What is it used for?

• Supplementing calcium in the diet when requirements are higher than normal, for example during childhood, pregnancy, breastfeeding or in old age.
• Treating calcium deficiency.
• Osteoporosis.
• Preventing the absorption of phosphate from the gut in people with kidney failure (phosphate binder).

How do I take it?

• Calcichew tablets should be taken just before, during or just after a meal. The tablets should be chewed or sucked and not swallowed whole.
• If Calcichew tablets are being taken as a calcium supplement (including for osteoporosis) then two or three tablets should be taken daily, preferably in divided doses, eg two in the morning and one in the evening. Follow the instructions given by your doctor or pharmacist.
• If you have kidney failure and are taking these tablets to prevent the absorption of phosphate, the dose will depend on your blood phosphate levels. Follow the instructions given by your doctor.

Warning!

• If you have mild to moderate kidney failure or raised levels of calcium in your urine (hypercalciuria) the amount of calcium in your blood and urine should be regularly monitored while you are taking this medicine.
• If you have a history of kidney stones, the amount of calcium excreted in your urine should be monitored while you are taking this medicine.

Use with caution in

• People with a history of kidney stones (nephrolithiasis).
• Kidney failure.
• Sarcoidosis.
• People with osteoporosis due to long periods of inactivity, for example prolonged bed-rest or paralysis of the legs.

Not to be used in

• People with a high level of calcium in their blood (hypercalcaemia), for example as a result of bone marrow cancer or cancer that has spread to the bones, overactivity of the parathyroid glands (hyperparathyroidism), sarcoidosis or vitamin D poisoning.
• People with very high levels of calcium in their urine (hypercalciuria).
• Kidney stones.
• Severely decreased kidney function that is not treated by kidney dialysis.
• Calcichew tablets contain sorbitol and isomalt and should not be taken by people with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency.
• Calcichew tablets contain aspartame, which is a source of phenylalanine. As a result, Calcichew tablets may not be suitable for people with phenylketonuria or who are intolerant to phenylalanine.

This medicine should not be used if you are allergic to any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

• This medicine is safe to take during pregnancy at the recommended doses. However, you should check with your doctor or midwife if it is necessary for you to take a calcium supplement during your pregnancy. Not all pregnant women need to take supplements; you may be getting enough nutrients from your diet.
• There are no known harmful effects when this medicine is used by breastfeeding mothers. However, you should only use this medicine after consulting your doctor.

Label warnings

• This medication is to be sucked or chewed.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.

• Constipation.
• Diarrhoea.
• Pain in the stomach and abdominal area.
• Excess gas in the stomach and intestines (flatulence).
• Nausea.
• Indigestion.

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to make sure that the combination is safe.

Calcium carbonate may reduce the absorption of tetracycline antibiotics (eg tetracycline, minocycline, doxycycline) and quinolone antibiotics (eg ciprofloxacin, norfloxacin, nalidixic acid) from the gut and could make them less effective. If you are prescribed a course of one of these types of antibiotics it is recommended that you take the antibiotic at least two hours before or four to six hours after taking this medicine. Ask your pharmacist for further advice.

Calcium salts may also reduce the absorption from the gut of the following medicines:

• bisphosphonates, eg etidronate
• eltrombopag
• iron supplements such as ferrous sulphate
• levothyroxine
• sodium fluoride
• strontium ranelate
• zinc.

To avoid the calcium stopping these medicines from being adequately absorbed, your dose of Calcichew should be separated from these medicines by at least four hours. Ask your pharmacist for further advice.

Thiazide diuretics, such as bendroflumethiazide, reduce the amount of calcium excreted in the urine, and this can increase the amount of calcium in the blood. If you are taking a thiazide diuretic in combination with this medicine you should have regular blood tests to monitor the level of calcium in your blood.

People taking digoxin or other cardiac glycosides may have an increased risk of abnormal heart rhythms if they experience abnormally high blood calcium levels while taking this medicine.

Other medicines containing the same active ingredient

Adcal	Cacit
Calcium 500	Calcichew Forte

Calcium-sandoz and Sandocal are calcium supplements that contain different salts of calcium.