Etidronate

Etidronate is a prescription medication used for the treatment of symptomatic Paget's disease of bone and in the prevention and treatment of heterotopic ossification following total hip replacement or due to spinal cord injury. 

• Etidronate is available under the following different brand names: Didronel.

Common side effects of Etidronate include:

• stomach upset
• diarrhea
• headache
• confusion
• muscle cramps
• joint pain
• numbness or tingly feeling

Serious side effects of Etidronate include:

• new or worsening heartburn
• pain when swallowing
• chest pain
• swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
• hoarseness
• difficulty swallowing
• blisters on the skin

Rare side effects of Etidronate include:

• none 

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, coordination loss, unsteady, very stiff muscles, high fever, profuse sweating, or tremors.
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult dosage

Tablet

• 200 mg
• 400 mg

Paget disease

Adult dosage

• Initial 5-10 mg/kg orally once a day not to exceed 6 months or 11-20 mg/kg orally once a day not to exceed 3 months  
• Not to exceed 20 mg/kg/day
• Retreatment should be initiated ONLY after at least 90 Etidronate-free days AND evidence of active disease

Heterotopic ossification

Adult dosage

• Total hip replacement
  • 20 mg/kg orally once a day 1 month pre- and 3 months post-surgery (4 months total)  
• Spinal cord injury
  • 20 mg/kg orally once a day for 2 weeks, then 10 mg/kg once a day for 10 weeks (12 weeks total)
  • Initiate treatment as soon as possible post-injury, preferably before a diagnosis of heterotopic ossification

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, healthcare provider, or pharmacist first.

Etidronate has severe interactions with the following drug:

• human parathyroid hormone, recombinant

Etidronate has serious interactions with no other drugs

Etidronate has moderate interactions with the following drugs:

• aluminum hydroxide
• calcium acetate
• calcium carbonate
• calcium chloride
• calcium citrate
• calcium gluconate
• deferasirox
• magnesium supplement
• selenium
• sodium bicarbonate
• sodium citrate/citric acid
• sodium sulfate/magnesium sulfate/potassium chloride
• sodium sulfate/potassium sulfate/magnesium sulfate
• voclosporin

Etidronate has minor interactions with the following drugs:

• entecavir
• foscarnet
• teriparatide

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, health questions, or concerns.

Contraindications

• Osteomalacia
• Hypersensitivity
• Esophagus abnormalities (eg, stricture, achalasia) that delay esophageal emptying

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Etidronate?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Etidronate?”

Cautions

• Enterocolitis, renal impairment
• May cause local irritation of upper gastrointestinal (GI) mucosa
• Potentially causes severe esophagitis, esophageal ulcers and erosions
• Ensure adequate intake of calcium, vitamin D
• Osteonecrosis of the jaw can occur spontaneously and is generally associated with tooth extraction and/or local infection with delayed healing; known risk factors include invasive dental procedures (eg, tooth extraction, dental implants, boney surgery), diagnosis of cancer, concomitant therapies (e.g., chemotherapy, corticosteroids, angiogenesis inhibitors), poor oral hygiene, and co-morbid disorders; risk of osteonecrosis of the jaw may increase with duration of exposure to bisphosphonates
• Risk of severe bone, joint, and/or muscle pain
• At higher doses both resorption inhibition and bone growth inhibition increase
• Esophageal cancer risk (July 21, 2011, FDA safety communication)
• Conflicting findings exist from studies evaluating the risk of esophageal cancer with oral bisphosphonates
• Esophagitis and other esophageal events have been reported, particularly in patients who do not follow the specific directions for the use of oral bisphosphonates (eg, sit up or stand after administration, take with a full glass of water)
• An ongoing review of data from published studies to evaluate whether the use of oral bisphosphonate drugs is associated with an increased risk of cancer of the esophagus is currently being conducted by the FDA
• The FDA has not concluded that taking an oral bisphosphonate drug increases the risk of esophageal cancer
• There are insufficient data to recommend endoscopic screening of asymptomatic patients
• FDA will continue to evaluate all available data supporting the safety and effectiveness of bisphosphonate drugs and will update the public when more information becomes available
• Instruct patients to contact their healthcare provider if they develop symptoms of esophagitis (eg, swallowing difficulties, chest pain, new or worsening heartburn, trouble, or pain when swallowing)

Pregnancy and Lactation

• Use with caution if the benefits outweigh the risks during pregnancy
• Lactation
  • Excretion in milk unknown; use with caution