Usage
Ibandronic acid is prescribed for the treatment and prevention of osteoporosis in postmenopausal women. It is also used to prevent skeletal events (pathological fractures, bone complications requiring radiotherapy or surgery) in patients with breast cancer and bone metastases. Ibandronic acid also can be used to treat hypercalcemia of malignancy. It is pharmacologically classified as a bisphosphonate.
Ibandronic acid works by inhibiting osteoclast-mediated bone resorption, thereby reducing bone turnover and increasing bone mineral density.
Alternate Names
Ibandronate sodium, ibandronic acid monosodium salt monohydrate. Brand names include Bonviva, Boniva.
How It Works
Pharmacodynamics: Ibandronic acid binds to hydroxyapatite crystals in bone, preferentially binding to sites of active bone resorption. It inhibits osteoclast activity, decreasing bone turnover and increasing bone mineral density. The precise mechanism of action of bisphosphonates on osteoclasts is unclear but appears to involve binding to hydroxyapatite followed by disruption of the cytoskeleton through inhibition of farnesyl pyrophosphate synthase, an enzyme in the mevalonate pathway.
Pharmacokinetics:
- Absorption: Oral absorption is rapid but reduced if taken with food or drinks other than plain water. Bioavailability is approximately 0.6%.
- Distribution: Distributes rapidly to bone with a half-life of 10-60 hours and to soft tissues with a half-life of 10-72 hours.
- Metabolism: Not extensively metabolized.
- Elimination: Primarily eliminated renally as unchanged drug. The terminal half-life is 10-72 hours, thought the effect on bone can last for weeks to months after treatment discontinuation.
Dosage
Standard Dosage
Adults:
- Osteoporosis Treatment and Prevention: 150 mg orally once a month or 2.5 mg orally once daily. Monthly administration should be on the same date each month. Daily doses should be taken in the morning, at least 60 minutes before the first food or drink of the day (other than water).
- Prevention of Skeletal Events in Breast Cancer with Bone Metastases: 50 mg orally once daily.
Children: Ibandronic acid is not recommended for use in patients under 18 years of age due to insufficient data on safety and efficacy.
Special Cases:
- Elderly Patients: No dosage adjustment is necessary.
- Patients with Renal Impairment:
- Mild to moderate renal impairment (CLcr ≥ 30 mL/min): No dosage adjustment necessary for the monthly 150mg dose. For the daily 50 mg dose for the prevention of skeletal events in breast cancer and bone metastases, no adjustment is necessary for mild renal impairment (CLcr ≥ 50ml/min), dosage adjustments are needed for moderate and severe renal impairment (see below).
- Moderate renal impairment (CLcr 30 to <50 mL/min) : 50 mg every other day for prevention of skeletal events.
- Severe renal impairment (CLcr < 30 mL/min): 50 mg once weekly.
- Patients with Hepatic Dysfunction: No dosage adjustment is required.
- Patients with Comorbid Conditions: Individualized dosage adjustments may be needed. Consider interactions with other medications.
Clinical Use Cases
Ibandronic acid is not indicated for intubation, surgical procedures, mechanical ventilation, intensive care unit (ICU) use, or emergency situations like status epilepticus or cardiac arrest. Its primary indications are related to osteoporosis and bone metastases.
Dosage Adjustments
Dose adjustments may be necessary in patients with renal impairment as outlined above, or in patients with other conditions or medications affecting drug clearance.
Side Effects
Common Side Effects
Back pain, dyspepsia, pain in extremity, diarrhea, headache, and myalgia. Acid reflux, difficulty swallowing, heartburn, esophageal ulcers and nausea have also been reported.
Rare but Serious Side Effects
Esophagitis, osteonecrosis of the jaw, atypical femoral fractures, hypocalcemia, atrial fibrillation, musculoskeletal pain.
Long-Term Effects
Osteonecrosis of the jaw, atypical femoral fractures, esophageal cancer.
Adverse Drug Reactions (ADR)
Hypocalcemia, angioedema, hypersensitivity reactions including anaphylaxis.
Contraindications
- Hypocalcemia
- Abnormalities of the esophagus which delay esophageal emptying such as stricture or achalasia
- Inability to stand or sit upright for at least 60 minutes
- Hypersensitivity to ibandronic acid or any components of the formulation
Drug Interactions
- Antacids, calcium, magnesium, iron or aluminum supplements: Can reduce absorption of ibandronic acid. Administer ibandronate at least 60 minutes before these supplements.
- Aspirin and other NSAIDs: May increase risk of gastrointestinal irritation.
- H2 blockers (eg, ranitidine) or proton pump inhibitors (eg, omeprazole): May increase risk of hypocalcemia.
Pregnancy and Breastfeeding
Ibandronic acid is contraindicated during pregnancy and breastfeeding as it may cause fetal harm and can be passed to the baby through breast milk. FDA Pregnancy Category C.
Drug Profile Summary
- Mechanism of Action: Inhibits osteoclast-mediated bone resorption.
- Side Effects: Common: Back pain, dyspepsia, extremity pain, diarrhea, headache, myalgia. Serious: Esophagitis, osteonecrosis of the jaw, atypical femoral fractures.
- Contraindications: Hypocalcemia, esophageal abnormalities, inability to remain upright for 60 minutes, hypersensitivity.
- Drug Interactions: Antacids, calcium supplements, NSAIDs.
- Pregnancy & Breastfeeding: Contraindicated.
- Dosage: Osteoporosis: 150 mg monthly or 2.5 mg daily; Metastatic bone disease (prevention of skeletal events): 50 mg daily.
- Monitoring Parameters: Serum calcium, bone mineral density, signs and symptoms of esophagitis, jaw pain.
Popular Combinations
Calcium and vitamin D supplements are often prescribed with ibandronic acid to ensure adequate intake for bone health.
Precautions
- Ensure adequate intake of calcium and vitamin D.
- Monitor for signs and symptoms of esophagitis.
- Dental examination before starting therapy is recommended to minimize the risk of osteonecrosis of the jaw.
- Monitor for musculoskeletal pain.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Ibandronic Acid?
A: For osteoporosis treatment and prevention: 150 mg orally once a month or 2.5 mg orally once daily. For the prevention of skeletal events in patients with breast cancer and bone metastases: 50 mg orally once daily.
Q2: How should Ibandronic Acid be administered?
A: Orally, with a full glass of plain water (180-240 ml) while the patient is in an upright position (sitting or standing). No other food, drinks, or medications should be taken for at least 60 minutes before and after administration.
Q3: What are the most common side effects?
A: Back pain, indigestion, extremity pain, diarrhea, headache, and muscle pain.
Q4: What are the serious side effects of Ibandronic Acid?
A: Esophagitis, osteonecrosis of the jaw (ONJ), atypical femoral fractures, and severe hypocalcemia.
Q5: Who should not take Ibandronic Acid?
A: Patients with hypocalcemia, esophageal abnormalities, inability to remain upright for at least 60 minutes, and hypersensitivity to the drug. Also contraindicated in pregnancy and breastfeeding.
Q6: Are there any drug interactions I should be aware of?
A: Avoid concomitant use with antacids, calcium supplements, and NSAIDs. These can interfere with ibandronic acid absorption or exacerbate GI side effects.
Q7: What precautions should I take when prescribing Ibandronic Acid?
A: Ensure adequate calcium and vitamin D intake. Advise patients to maintain upright posture after administration. Counsel patients on potential side effects, including esophagitis and ONJ. Monitor renal function, especially in patients with pre-existing renal impairment.
Q8: Can Ibandronic Acid be used in patients with renal impairment?
A: Dosage adjustments are necessary for patients with moderate to severe renal impairment. It is not recommended in patients with creatinine clearance <30mL/min.
Q9: Can Ibandronic Acid be used during pregnancy or breastfeeding?
A: No. Ibandronic Acid is contraindicated in pregnancy and breastfeeding.
Q10: What is the duration of Ibandronic acid therapy?
A: The optimal duration of treatment varies depending on the individual patient’s risk factors and response to therapy. Periodically re-evaluate the need for continued therapy.
