CO Etidrocal

Brand Name: CO Etidrocal
Common Name: etidronate - calcium carbonate

How does this medication work? What will it do for me?

This medication contains two different medications to be taken at different times: etidronate and calcium carbonate. Etidronate belongs to a family of medications known as bisphosphonates. Etidronate and calcium carbonate are used in combination to treat and prevent osteoporosis in postmenopausal women. It can also be used to prevent steroid-induced osteoporosis (osteoporosis caused by taking corticosteroids such as prednisone for long periods of time).

It is used to increase the density of bones, making them less likely to break. Calcium is one of the building blocks of bones and therefore helps to prevent bone loss.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

How should I use this medication?

This medication is taken in 90-day cycles that are repeated. Each cycle consists of 14 white etidronate 400 mg tablets (to be taken once daily on an empty stomach with a full glass of water) and 76 blue calcium tablets (to be taken once daily for the following 76 days, with a full glass of water).

The white etidronate tablets should be taken at bedtime with a full glass of water on an empty stomach (at least 2 hours before or after eating). Food in the stomach, especially if it is high in calcium, may prevent etidronate from being properly absorbed into the body. Vitamins with minerals such as iron and calcium, laxatives containing magnesium, and antacids containing calcium or aluminum should not be taken within 2 hours before or after taking etidronate (the white tablets in the first 2 weeks of therapy).

The blue calcium tablets should be taken at bedtime with a full glass of water, on either an empty or full stomach. If you find the tablets difficult to swallow, you can crush or chew them.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor in a cyclical fashion. If you miss a dose of your medication, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and carry on with your regular dosing schedule. Do not take a double dose for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

What form(s) does this medication come in?

The CO Etidrocal 90-day therapy is supplied in a unit-of-use dispensing system that consists of patient information and the therapy tablets on 5 blister cards.

Etidronate Disodium
The first blister card contains a 14-day supply of 14 tablets. Each off-white, capsule-shaped, scored tablet, embossed "ED4" on one side and the Cobalt logo on the other side, contains etidronate disodium 400 mg. Nonmedicinal ingredients: magnesium stearate, microcrystalline cellulose, pregelatinized starch, and starch (corn).

Calcium Carbonate
The remaining four blister cards contain a 76-day supply of 76 tablets. Each blue, biconvex, plain-faced, oblong, film-coated tablet contains calcium carbonate 1,250 mg, each providing 500 mg elemental calcium. Nonmedicinal ingredients: acacia, carnauba wax, FD&C Blue No. 2 Aluminum Lake, maltodextrin, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polyvinyl alcohol, sodium croscarmellose, talc, and titanium dioxide.

Who should NOT take this medication?

Do not use this medication if you:

  • are allergic to etidronate disodium or any ingredients of the medication
  • have osteomalacia (softening of the bones)

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • diarrhea
  • dizziness
  • flatulence
  • headache
  • heartburn
  • nausea

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • bone fractures, especially of the thigh bone
  • hives
  • skin rash or itching
  • swelling of the arms, face, legs, lips, throat, or tongue

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • blood disorders with symptoms of bleeding, bruising and increased infection
  • pain and swelling of the tongue or esophagus (the tube connecting the mouth and stomach)
  • skin reactions (rash, sores, blisters) involving mucous membranes
  • worsening of asthma
  • worsening of stomach and intestinal ulcers

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.


December 19, 2011

Health Canada has issued new restrictions concerning the use of etidronate - calcium carbonate. To read the full Health Canada Advisory, visit Health Canada's web site at

Dental procedures: A dental examination and any necessary dental procedures should be considered before you start treatment with etidronate-calcium if you have one of the following risk factors: cancer; chemotherapy, radiotherapy of the head or neck, treatment with corticosteroids, or dental problems or dental infections.

Gastrointestinal disorder: If you have a gastrointestinal disorder that makes you prone to diarrhea (for example colitis) you may experience increased frequency of bowel movements and diarrhea. Talk to your doctor.

Kidney function: People with reduced kidney function or a history of kidney stones should be closely monitored by their doctor while taking this medication.

Pregnancy: This medication should not be used during pregnancy. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known whether etidronate is excreted in human milk. It is not intended for use during breast-feeding. If you are a breast-feeding mother and are taking etidronate, it may affect your baby. Talk to you doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

What other drugs could interact with this medication?

There may be an interaction between the etidronate (first 14 days) portion of etidronate - calcium and any of the following:

  • antacids taken within 2 hours of taking etidronate
  • calcium supplements taken within 2 hours of taking etidronate
  • magnesium-containing products (such as laxatives) taken within 2 hours of taking etidronate
  • vitamins containing minerals such as calcium, iron, and magnesium taken within 2 hours of taking etidronate

There may be an interaction between etidronate - calcium and any of the following:

  • demeclocycline
  • minocycline
  • quinolones (e.g., ciprofloxacin, ofloxacin)
  • sodium polystyrene sulfonate
  • tetracycline
  • warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

All material © 1996- MediResource Inc. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

  • This site is best viewed using IE 5.5 or above