How does it work?

Didronel PMO contains two different types of tablet, Didroneland Cacit. The Didronel tablets contain the active ingredient etidronatedisodium, which is a type of medicine known as a bisphosphonate.Bisphosphonates are medicines that prevent the breakdown of bone. The Cacittablets contain calcium carbonate and are used as a calciumsupplement.

Bone is not a static structure. It is continually shaped,reformed and rebuilt by cells called osteoblasts and osteoclasts. These cellscontinously deposit and remove calcium and phophorous, stored in a proteinnetwork that makes up the structure of the bone. Old bone is broken down by theosteoclasts and new bone is formed by the osteoblasts.

In women at the menopause, blood levels of the female hormoneoestrogen start to decrease. This results in an increase in bone breakdown bythe osteoclasts, which can lead to a loss of bone density. Bone loss isparticularly rapid for the first ten years after the menopause and it may leadto the development of osteoporosis - a condition in which the bones become weakand brittle and break (fracture) more easily.

Osteoporosis can also occur in men and as a result of long-termtreatment with corticosteroid medicines such as prednisolone.

Etidronate is used both to prevent bone loss in people who areat risk of developing osteoporosis, and to prevent fractures in people whoalready have osteoporosis. The medicine works by binding very tightly to thebone and preventing the calcium being removed by the osteoclasts. This stopsthe osteoclasts from breaking down the bone, which helps to keep the bonesstrong and less likely to break.

Etidronate is used to treat osteoporosis, and also to preventbone loss in postmenopausal women at risk of developing osteoporosis. Riskfactors for osteoporosis include a history of smoking, a family history ofosteoporosis, early menopause, thin body build and long-term treatment withcorticosteroids, eg prednisolone.

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

The Didronel and Cacit tablets are taken as a 90 day cyclicalregimen to slow the breakdown of bone. One Didronel tablet is taken each dayfor the first 14 days of the treatment cycle, followed by one Cacit tablet eachday for the remaining 76 days.

What is it used for?

• Treatment of osteoporosis.
• Preventing bone loss in women who have passed the menopause and are at risk of osteoporosis.
• Prevention and treatment of osteoporosis caused by long-term treatment with corticosteroids such as prednisolone.

How do I take it?

• One Didronel tablet should be taken once a day for 14 days, followed by one Cacit tablet once a day for 76 days.
• Each Didronel tablet should be swallowed with water on an empty stomach. You should not eat or drink anything other than water in the two hours before and the two hours after taking a Didronel tablet. This is because food and some drinks (particularly milk and dairy products) can interfere with the absorption of the medicine from the gut and hence make it less effective.
• You should not take antacids or mineral supplements in the two hours before or after taking your Didronel tablets, as these can also interfere with the absorption of the medicine from the gut. See the end of this page for more information.
• Cacit tablets can be taken either with or without food. Each Cacit tablet should be dissolved in a glass of water before taking.

Warning!

• If you have kidney problems or have ever had a kidney stone, the amount of calcium in your blood and urine should be regularly monitored while you are taking this medicine.
• The class of medicines that etidronate disodium belongs to (bisphosphonates) has been associated with a rare condition called osteonecrosis of the jaw. The majority of cases of this condition have been in cancer patients treated with bisphosphonates by injection into a vein, and many of these people were also having treatment with chemotherapy or corticosteroids. However, the condition has also been seen in people taking bisphosphonates by mouth. The risk may also be increased by poor oral hygiene, dental problems such as gum disease or poorly fitting dentures, teeth extractions, oral surgery and smoking. For this reason, you should have a dental examination and, if necessary, appropriate preventive dentistry, before you start treatment with this medicine. Discuss this with your doctor. It is important to look after your mouth and teeth as much as possible while you are taking this medicine. You should have regular check-ups with your dentist and get advice straight away if you have any problems with your mouth or teeth. When you see a dentist during treatment, make sure they know you are taking this medicine. Invasive dental procedures such as tooth extraction or surgery should be avoided if possible.
• Some people being treated with bisphosphonates (mainly people having long-term treatment for osteoporosis) have experienced an unusual fracture of their thigh bone. For this reason it is important to let your doctor know if you get any pain in your thighs, hips or groin while you are having treatment with this medicine. These symptoms could be an early indication of a possible fracture.
• Cacit tablets contain the colouring sunset yellow (E110), which can cause an allergic-type reaction. This allergy is more common in people who are allergic to aspirin.

Use with caution in

• Decreased kidney function.
• History of kidney stones.
• People with chronic (long-term) diarrhoea.

Not to be used in

• People with softening of the bones due to a deficiency in vitamin D or calcium (osteomalacia).
• Severely decreased kidney function.
• People with a high level of calcium in their blood (hypercalcaemia) or urine (hypercalciuria).
• Pregnancy.
• Breastfeeding.
• Rare hereditary problems of fructose intolerance.
• This medicine is not recommended for children.

This medicine should not be used if you are allergic to one orany of its ingredients. Please inform your doctor or pharmacist if you havepreviously experienced such anallergy. If you feel you haveexperienced an allergic reaction, stop using this medicine and inform yourdoctor or pharmacist immediately.

Pregnancy and breastfeeding

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

• The safety of this medicine in pregnancy has not been established. It should not be taken by women who are pregnant, and women who could get pregnant should use an effective method of contraception to prevent pregnancy while taking this medicine. Seek further medical advice from your doctor.
• It is not known if this medicine passes into breast milk. It should not be used by women who are breastfeeding. Seek medical advice from your doctor.

Label warnings

• Follow the printed instructions you have been given with this medication.

Side effects

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

• Diarrhoea.
• Feeling sick.
• Flatulence (wind).
• Indigestion.
• Abdominal pain.
• Constipation.
• Vomiting.
• Inflammation of the stomach (gastritis).
• Worsening of peptic ulcer.
• Headache.
• Pins and needles sensations.
• Confusion.
• Pain in the joints (arthralgia or arthritis).
• Severe swelling of lips, face or tongue (angioedema).
• Rash or itching.
• Worsening of asthma.
• Decreased levels of white blood cells or platelets in the blood.
• Burning of the tongue.
• Hair loss.
• Osteonecrosis of the jaw (see warning section above).
• Unusual fracture of the thigh (see warning section above).

The side effects listed above may not include all of the sideeffects reported by the medicine'smanufacturer. For moreinformation about any other possible risks associated with this medicine,please read the information provided with the medicine or consult your doctoror pharmacist.

How can this medicine affect other medicines?

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

The following medicines should not be taken in the two hoursbefore or the two hours after taking your Didronel tablets, as they may reduce theabsorption of the medicine from the gut and make it less effective:

• antacids (indigestion remedies)
• calcium supplements
• iron supplements
• laxatives containing magnesium
• mineral supplements
• multivitamins containing minerals such as calcium, iron, magnesium or zinc
• zinc supplements.

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 while you are taking the Cacit tablets, you should not take the Cacit tablet within three hours of taking a dose of the antibiotic. Ask your pharmacist for further advice.

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

• 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 Cacit dose should be separated from these medicines by at least three 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.

Vitamin D increases the absorption of calcium. Do not takevitamin D supplements while taking this medicine without consulting your doctorfirst.