Apo-Etidronate: Uses, Side Effects and Dosage

ABOUT THIS MEDICATION

What the medication is used for:

• Treatment of symptomatic Paget’s disease of

  the bone

• Short-term (30 to 90 days) maintenance of

  blood calcium levels following treatment with etidronate disodium l.V. Infusion for patients with hypercalcemia of malignancy (i.e. high blood calcium secondary to malignancy disease)

What it does:

To understand how the APO-ETIDRONATE therapy works, it is important to understand your bone health.

Bone is a living tissue that your body constantly renews. In this normal process, your body breaks down old bone tissue and replaces it with new bone. In Paget’s disease, this process is abnormal and accelerated. APO-ETIDRONATE acts on bones by slowing the abnormal and accelerated rate of bone turnover in Paget’s disease.

People with Paget’s disease can experience bone pain, bone deformity and vascular disorder (i.e blood vessel disorder associated with Paget’s disease). In research studies, etidronate disodium therapy improved Paget’s symptoms including the reduction of bone pain in patients with Paget’s disease.

APO-ETIDRONATE can also be used to treat hypercalcemia of malignancy or high blood calcium, which is a condition that occurs in 8 to 20% of patients with malignant diseases. By slowing the rate of bone turnover, APO-ETIDRONATE also reduces the release of calcium from the bones to the blood stream, which in turn reduces the blood calcium level to an acceptable level.

When it should not be used:

APO-ETIDRONATE is not suitable for everyone.

APO-ETIDRONATE should not be used:

• If you have unresolved osteomalacia, which is a condition of inadequate or delayed bone mineralization (formation).
• If you are allergic to APO-ETIDRONATE and any of its ingredients (see below).

What the medicinal ingredient is:

Etidronate disodium

What the nonmedicinal ingredients are:

Magnesium stearate and crospovidone.

What dosage forms it comes in:

Tablets, 200mg and 400 mg

WARNINGS AND PRECAUTIONS

Before you use APO-ETIDRONATE talk to your doctor or pharmacist if:

• You have unresolved osteomalacia, which is a condition of inadequate or delayed bone mineralization (formation).
• You have problems with your kidneys, stomach or intestines.

• You are pregnant or nursing.

• You are allergic to APO-ETIDRONATE and any of its ingredients.
• You have sores in the mouth. This can lead to osteonecrosis of the jaw.

Your doctor may check if you:

• smoke
• have or have had teeth and/or gum disease
• have dentures that do not fit well
• have other relevant medical conditions at the same time, such as; low red blood cell count (called anemia) or if your blood cannot form clots in the normal way.

Your doctor may tell you to stop taking APO- ETIDRONATE until all sores in your mouth are healed.

• 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. If so, a dental examination and any necessary dental procedures should be considered before you start treatment with APO-ETIDRONATE.

Be sure to tell your health care providers, including doctors and dentists, about all

medicines you are taking, including APO-ETIDRONATE.

Patients with Paget’s disease of bone should maintain an adequate intake of calcium and vitamin D.

INTERACTIONS WITH THIS MEDICATION

If taken with some other medicines, the effects of APO-ETIDRONATE or the effects of other medicines may be changed. Please check with your doctor or pharmacist before taking other medications with APO-ETIDRONATE.

Drugs that may interact with APO-ETIDRONATE include corticosteroid, phosphate, calcitonin, furosemide, warfarin or mithramycin.

To maximize the absorption, the following foods and medicines should not be taken within 2 hours of taking APO-ETIDRONATE: Antacids, vitamins with mineral supplements such as iron, calcium supplements, laxatives containing magnesium and foods, especially food high in calcium, such as milk or milk products.

PROPER USE OF THIS MEDICATION

As with all medications, it is important to take as directed by your doctor.

Usual dose:

For Paget’s disease, the recommended initial dose of APO-ETIDRONATE for most patients is 5 mg per kilogram of bodyweight per day, not to exceed a period of 6 months.

For hypercalcemia of malignancy, the recommended dose is 20 mg per kilogram of bodyweight per day for

30 days.

Overdose:

If you think you have taken too much APO-ETIDRONATE, contact your healthcare professional, hospital emergency department or regional Poison Control Centre immediately, even if there are no symptoms.

Missed Dose:

If you miss a day (or more) of the treatment, do not take 2 tablets the same day. Take 1 tablet on the day you remember and continue with the therapy.

SIDE EFFECTS AND WHAT TO DO ABOUT THEM

With any medication, there is some chance of side effects. The most common side effects observed with APO-ETIDRONATE are nausea and diarrhea.

Rarely reported side effects include confusion, a burning sensation of the tongue, hair loss, and a sensation of numbness, prickling or tingling.

In patients with Paget’s disease, joint pain or new, increased or returning bone pain may occur. In some patients, the pain resolved while etidronate disodium was continued, but persisted for several months in others. On occasion, APO-

ETIDRONATE may have to be stopped.

Ophthalmologic

Ocular disturbances including conjunctivitis, uveitis, episcleritis, iritis and scleritis have been reported with bisphosphonate use. There have been published reports of conjunctivitis with etidronate. Patients with ocular events other than uncomplicated conjunctivitis should be referred to an ophthalmologist for evaluation. Treatment may need to be discontinued.

Atypical Subtrochanteric and Diaphyseal Femoral Fractures

Atypical, low-energy, or low trauma fractures of the femoral shaft have been reported in bisphosphonate treated patients. These fractures can occur anywhere in the femoral shaft from just below the lesser trochanter to above the supracondylar flare and are transverse or short oblique in orientation without evidence of comminution. Atypical femur fractures most commonly occur with minimal or no trauma to the affected area. They may be bilateral and many patients report prodromal pain in the affected area, usually presenting as dull, aching thigh pain, weeks to months before a complete fracture occurs. Poor healing of these fractures was also reported. Any patient with a history of bisphosphonate exposure who presents with thigh or groin pain should be suspected of having an atypical fracture and should be evaluated to rule out an incomplete femur fracture. Patients presenting with an atypical femur fracture should also be assessed for symptoms and signs of fracture in the contralateral limb. Interruption of bisphosphonate therapy should be considered pending a risk/benefit assessment.

Very rarely patients have reported non-healing jaw wounds while receiving drugs in this class, such as etidronate disodium. Consult your doctor if you experience persistent pain in your mouth,

teeth or jaw, or if your gums or mouth heal poorly.

IMPORTANT SERIOUS SIDE EFFECTS, HOW OFTEN THEY HAPPEN AND WHAT TO DO ABOUT THEM

This is not a complete list of side effects. For any unexpected effects while taking APO-ETIDRONATE, contact your doctor or pharmacist.

HOW TO STORE IT

Store at controlled room temperature (15°C to 30°C). Protect from moisture.

Keep out of reach and sight of children.

Reporting Side Effects

You can report any suspected side effects associated with the use of health products to Health Canada by:

• Visiting the Web page on Adverse Reaction

  Reporting (https://www.canada.ca/en/health-canada/services/drugs-health-

  products/medeffect-canada/adverse-reaction-reporting.html) for information on how to report online, by mail or by fax; or

• Calling toll-free at 1-866-234-2345.

NOTE: Contact your health professional if you need information about how to manage your side effects. The Canada Vigilance Program does not provide medical advice.

MORE INFORMATION

For more information, please contact your doctor, pharmacist or other healthcare professional.

This leaflet plus the full product monograph, prepared for health professionals, can be obtained by contacting DISpedia, Apotex's Drug Information Service, at

1-800-667-4708.

This leaflet can also be found at

http://www.apotex.ca/products.

Date of Revision: December 07, 2017