Etidronic acid is a diphosphonate which affects calcium metabolism. It inhibits ectopic calcification and slows down bone resorption and bone turnover. As a member of the family of drugs known as bisphosphonates, etidronate differs from endogenous pyrophosphate in its resistance to enzymatic hydrolysis. This agent adsorbs to hydroxyapatite cells and reduces the number of osteoclasts, thereby inhibiting abnormal bone resorption. Etidronate may also directly stimulate bone formation by osteoblasts.
Etidronic acid a diphosphonate which affects calcium metabolism. It inhibits ectopic calcification and slows down bone resorption and bone turnover. Etidronic acid is a first generation (non-nitrogenous) bisphosphonate in the same family as clodronate and tiludronate. Etidronic acid affects calcium metabolism and inhibits bone resorption and soft tissue calcification. Of the etidronic acid that is resorbed (from oral preparation) or infused (for intravenous drugs), about 50% is excreted unchanged by the kidney. The remainder has a very high affinity for bone tissue and is rapidly absorbed onto the bone surface. Etidronic acid has been shown to prevent or delay skeletal-related events and decrease bone pain as well as normalize calcium levels in the presence of hypercalcemia.
Mechanism of action of Etidronic acid
Bisphosphonates, when attached to bone tissue, are absorbed by osteoclasts, the bone cells that break down bone tissue. Although the mechanism of action of non-nitrogenous bisphosphonates has not been fully elucidated, available data suggest that they bind strongly to hydroxyapatite crystals in the bone matrix, preferentially at the sites of increased bone turnover and inhibit the formation and dissolution of the crystals. Other actions may include direct inhibition of mature osteoclast function, promotion of osteoclast apoptosis, and interference with osteoblast-mediated osteoclast activation. Etidronic acid does not interfere with bone mineralization. In malignancy-related hypercalcemia, etidronic acid decreases serum calcium by inhibiting tumor-induced bone resorption and reducing calcium flow from the resorbing bone into the blood. Etidronic acid also reduces the morbidity of osteolytic bone metastases by inhibiting tumor-induced bone resorption. The etidronic acid may promote osteoclast apoptosis by competing with adenosine triphosphate (ATP) in the cellular energy metabolism. The osteoclast initiates apoptosis and dies, leading to an overall decrease in the breakdown of bone.
Indications of Etidronic acid
- Hypercalcemia
- Ossification, Heterotopic
- Prevention of osteoporosis
- Paget’s disease
- Treatment of osteoporosis in post-menopausal women to prevent fractures
- Treatment of osteoporosis in men to prevent fractures
- Prevention and treatment of corticosteroid-induced osteoporosis and prevention of bone loss in post-menopausal women considered at risk of developing osteoporosis.
- Prophylaxis and treatment of female osteoporosis
- Bone destruction
- Prevention and treatment of corticosteroid-associated osteoporosis together with supplements of calcium and vitamin D
- Treatment for osteogenesis imperfecta in patients of 18 years or older
- Dental implants coating (experimental)
- Osteogenesis imperfecta
- Osteoporosis caused by glucocorticoid
- 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.
Contra-Indications of Etidronic acid
- Acute inflammations of the gastrointestinal tract (esophagitis, gastritis, ulcerations)
- Clinically manifest osteomalacia
- Certain malformations and malfunctions of the esophagus (strictures, achalasia)
- Inability to stand, walk, or sit for 30 minutes after oral administration
- Renal impairment with a creatinine clearance below 30ml/min
- Hypersensitivity to alendronate or another ingredient
- Hypocalcemia
- Pregnancy and breastfeeding
- Patients below 18 yrs. of age, as no clinical data exists
- Signs of colic, which is usually self-limiting, occurs in 30-45% of horses.
- Tachycardia
- Electrolyte disturbances: primarily calcium, magnesium, and potassium, which can last for several hours. Caution should be used in horses with disease processes that could be affected by electrolyte disturbances, such as hyperkalemic periodic paralysis or cardiac disease.
- Kidney damage: it is eliminated by the kidney and is not recommended for use in animals with impaired renal function.
- Less serious reactions include stiffness of the neck, decreased appetite, fever, and increased urination.
The dosage of Etidronic acid
Strengths
Etidronic Acid is available in the following doses:
- Etidronate 200 Mg Oral Tablet
- Etidronate 400 Mg Oral Tablet
- Etidronate 50 Mg/ml Intravenous Solution
Side Effects of Etidronic acid
The most common
- Abdominal or stomach pain
- feeling of heaviness, pain, warmth and/or swelling in a leg or in the pelvis
- sudden tingling or coldness in an arm or leg
- Nausea
- liver problems,
- stomach pain,
- vomiting,
- Dizziness
- Burning, itching, stinging, redness, or other sign of irritation at the application site, rash
- a headache,
- increased intracranial pressure,
- meningeal signs,
- reversible hair loss or thinning, and
- fever.
Common
- chills or fever
- a headache, severe and throbbing
- joint or back pain
- muscle aching or cramping
- muscle pains or stiffness
- chest pressure or squeezing pain in the chest
- discomfort in arms, shoulders, neck or upper back
- excessive sweating
- sudden slow or difficult speech
- sudden drowsiness or need to sleep
- fast breathing
- sharp pain when taking a deep breath
- fast or slow heartbeat
- coughing up blood
- rust colored urine
- liver problems–nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes)
- decreased amount of urine
Rare
- Anxiety
- change in vision
- chest pain or tightness
- confusion
- a cough
- Agitation
- arm, back, or jaw pain
- blurred vision
- chest pain or discomfort
- convulsions
- extra heartbeats
- hallucinations
- a headache
- irritability
- lightheadedness
- mood or mental changes
- muscle pain or cramps
- muscle spasm or jerking of all extremities
- burning,
- stinging,
- severe pain in your upper stomach spreading to your back, nausea, and vomiting;
- signs of congestive heart failure–shortness of breath (even with mild exertion), coughwith mucus, fast heartbeats, swelling, rapid weight gain, sleep problems;
Drug Interactions of Etidronic acid
The etidronic acid may interact with following drugs, supplements & may change the efficacy of drugs
- NSAIDs (nonsteroidal anti-inflammatory drugs) such as ibuprofen, naproxen
- aspirin
- antacids
- proton pump inhibitors such as esomeprazole, lansoprazole, omeprazole,
- H2 blockers such as cimetidine, famotidine, nizatidine, ranitidine
- hormone therapy such as estrogens and estrogen agonist/blockers
- cancer chemotherapy treatments
- steroids such as dexamethasone, methylprednisolone, prednisone
The following medicines can lower the amount of risedronate that your body absorbs:
- antacids
- calcium supplements
- aluminum supplements
- magnesium supplements
- aspirin
- iron supplements
If you must take these medicines, wait at least 30 minutes after taking etidronate.
Pregnancy & Lactation
FDA pregnancy category C.
Pregnancy
Etidronate is not intended for use during pregnancy. If you become pregnant while taking this medication, contact your doctor immediately.
Lactation
It is not known if etidronate passes into breast milk. If you are a breastfeeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breastfeeding. The safety and effectiveness of using this medication have not been established for children.
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