etidronate disodium

et·i·dro·nate disodium (t-drnt)

n.

A drug that affects bone resorption and is used in the treatment of Paget's disease, heterotopic ossification, and hypercalcemia of malignancy.

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etidronate disodium

(ē´tdrō´nāt dīsō´dēm),
n brand name: Didronel IV;
drug class: antihypercalcemic;
action: decreases bone resorption and new bone development (accretion);
uses: Paget's disease, heterotopic ossification, hypercalemia of malignancy.

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etidronate disodium

Didronel

Pharmacologic class: Bisphosphonate

Therapeutic class: Bone resorption inhibitor, hypocalcemic agent

Pregnancy risk category B (oral use), C (I.V. use)

Action

Blocks calcium absorption, slowing bone metabolism and reducing bone resorption and formation

Availability

Injection: 300 mg/ampule in 6-ml ampules

Tablets: 200 mg, 400 mg

⊘Indications and dosages

➣ Paget's disease

Adults: 5 to 10 mg/kg P.O. daily as a single dose for up to 6 months, or 11 to 20 mg/kg P.O. daily for up to 3 months

➣ Heterotopic ossification after hip replacement

Adults: 20 mg/kg P.O. daily for 1 month before and 3 months after surgery

➣ Heterotopic ossification in spinal cord injury

Adults: Initially, 20 mg/kg P.O. daily for 2 weeks, decreased to 10 mg/kg P.O. daily for 10 weeks

➣ Hypercalcemia related to cancer

Adults: 7.5 mg/kg/day I.V. infused over at least 2 hours for 3 consecutive days; may continue infusion for up to 7 days if necessary. P.O. dosing may begin after last infusion.

Contraindications

• Hypersensitivity to drug or its components
• Severe renal impairment
• Osteomalacia (tablets)

Precautions

Use cautiously in:
• moderate renal impairment, long bone fractures, heart failure, hypocalcemia, hypovitaminosis D
• pregnant or breastfeeding patients
• children (safety not established).

Administration

• For I.V. use, dilute with 250 ml of normal saline solution. Infuse slowly over at least 2 hours.
• Give oral dose with water or juice 2 hours before meals.
• Make sure patient doesn't eat for 2 hours after receiving dose.
• Know that therapy longer than 3 months is not recommended.

Route	Onset	Peak	Duration
P.O. (Paget's)	1 mo	Unknown	1 yr
P.O. (ossif.)	Unknown	Unknown	Several mo
I.V. (hypercalc.)	24 hr	3 days	11 days

Adverse reactions

All reactions occur only with I.V. use unless otherwise noted.

CNS: seizures

GI: nausea, constipation, stomatitis

Hematologic: anemia

Metabolic: hypomagnesemia, hypophosphatemia, fluid overload

Musculoskeletal: bone pain and tenderness, fractures (all with oral use)

Respiratory: dyspnea

Skin: rash (with oral use)

Other: taste loss, metallic taste, fever

Interactions

Drug-drug. Antacids; buffers containing aluminum, calcium, iron, or magnesium; mineral supplements: decreased etidronate absorption

Calcitonin: additive hypocalcemic effect

Warfarin: increased prothrombin time

Drug-diagnostic tests. Blood urea nitrogen (BUN), creatinine: increased levels

Calcium, magnesium: decreased levels

Liver function tests: elevated values

Drug-food. Foods high in aluminum, calcium, iron, or magnesium: decreased etidronate absorption

Patient monitoring

• Monitor fluid intake and output.
☞ Watch for seizures.
• Monitor patient for GI discomfort. Divide doses as needed to ease symptoms.
• Assess bowel pattern. If constipation occurs, increase fluids and administer stool softeners, as prescribed.
• Monitor calcium, phosphorus, magnesium, creatinine, and BUN levels; liver function tests; and bone scans.

Patient teaching

• Instruct patient not to take drug with food because of decreased drug absorption.
• Tell patient not to consume high-calcium products, such as milk or antacids, within 2 hours of taking dose.
• Stress importance of eating a diet high in vitamin D and calcium.
• Advise patient to report bone pain or decreased range of motion.
• As appropriate, review all other significant adverse and life-threatening reactions and interactions, especially those related to the drugs, tests, and foods mentioned above.

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etidronate disodium Didronel® Metabolism An organic biphosphonate used to manage osteoporosis, Paget's disease of bone–osteitis deformans, heterotopic ossification, hypercalcemia of CA. See Coherence therapy, Osteoporosis.