IBANDRONATE SODIUM

Clinical safety rating: avoid

Contraindicated (not allowed)

How it works

Bisphosphonate that inhibits osteoclast-mediated bone resorption by binding to hydroxyapatite in bone matrix and interfering with the mevalonate pathway, leading to loss of osteoclast activity and induction of apoptosis.

What the body does with it

Metabolism	Not metabolized; eliminated renally via active tubular secretion and glomerular filtration. No known CYP450 involvement.
Excretion	Renal excretion of unchanged drug via glomerular filtration and tubular secretion; approximately 50-60% of absorbed dose is excreted unchanged in urine within 24 hours, with cumulative urinary excretion accounting for 50-80% of systemically absorbed dose; non-renal clearance (biliary/fecal) is negligible (<1%).
Half-life	Terminal elimination half-life ranges from 10 to 60 hours, with a mean of approximately 37 hours; due to high affinity for bone, the drug is slowly released from bone compartment, resulting in an extended terminal half-life of up to 90-160 hours in bone; clinical context: supports once-monthly oral dosing and once-every-3-months intravenous dosing for osteoporosis.
Protein binding	Approximately 84-88% bound to serum proteins, primarily albumin; binding is concentration-independent over therapeutic range (0.1-10 ng/mL).
Volume of Distribution	Apparent steady-state volume of distribution is approximately 90 L (1.3 L/kg for a 70 kg individual); extensive distribution into bone (hydroxyapatite), with bone uptake accounting for 40-50% of the dose; large Vd indicates extensive tissue binding, minimal distribution into red blood cells.
Bioavailability	Oral: absolute bioavailability is approximately 0.6% under fasting conditions (range 0.4-0.8%); coadministration with food or calcium reduces bioavailability significantly (up to 90% reduction); Intravenous: 100% bioavailability.
Onset of Action	Oral: suppression of bone resorption markers (e.g., serum CTX) begins within 1-3 days after a single dose, with maximal effect observed after 7-14 days; Intravenous: rapid onset with reduction in bone resorption markers within 24 hours.
Duration of Action	After single oral dose, suppression of bone turnover markers persists for at least 28 days; after intravenous bolus, effect lasts for approximately 3 months; sustained effect is due to long bone retention; clinical notes: supports monthly oral and quarterly IV dosing regimens.

Classification & Brands

Dosing & administration

150 mg orally once monthly for osteoporosis; 3 mg intravenously over 15-30 seconds every 3 months for osteoporosis; 6 mg intravenously over 15-30 minutes for metastatic bone disease (repeat every 3-4 weeks).

Dosage form	TABLET
Renal impairment	CrCl >=30 mL/min: no adjustment. CrCl <30 mL/min: not recommended for oral; IV: 2 mg every 3 months for osteoporosis; for malignancy, reduce dose or extend interval based on CrCl (e.g., CrCl 30-50: 4 mg; CrCl 18-29: 2 mg; <18: not studied).
Liver impairment	No dose adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B). Not studied in severe hepatic impairment (Child-Pugh C); use with caution.
Pediatric use	Safety and efficacy not established in pediatric patients (<18 years). No recommended dose.
Geriatric use	No specific dose adjustment based on age alone. Assess renal function and adjust dose accordingly (see renal adjustment). Monitor for renal toxicity, hypocalcemia, and musculoskeletal pain.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Calcium supplements and other oral medications can interfere with absorption Risk of esophageal irritation and osteonecrosis of the jaw.

Breastfeeding	Excreted into rat milk; human data unavailable. M/P ratio unknown. Discontinue nursing or drug due to potential for infant hypocalcemia and bone development interference.
Teratogenic Risk	Pregnancy Category C. First trimester: No adequate human studies; animal studies show fetal skeletal abnormalities. Second/third trimesters: Potential for fetal hypocalcemia and skeletal effects due to bisphosphonate incorporation into bone matrix. Avoid use in pregnancy unless clearly needed.

Warnings & precautions

■ FDA Black Box Warning

None

Side Effect Profile

Common Effects	Headache Musculoskeletal bone muscle or joint pain Heartburn Diarrhea Indigestion Dizziness Hypercholesterolemia high cholesterol Upper respiratory tract infection Urinary tract infection
Serious Effects

Absolute Contraindications

["Hypersensitivity to ibandronate or any component","Hypocalcemia","Inability to stand or sit upright for at least 60 minutes","Severe renal impairment (CrCl <30 mL/min)"]

Clinical Precautions

Precautions

["Severe and occasionally incapacitating bone, joint, or muscle pain","Osteonecrosis of the jaw, especially with invasive dental procedures","Atypical femur fractures","Hypocalcemia must be corrected before initiation","Renal impairment (CrCl <30 mL/min is not recommended)","Severe renal impairment and dialysis patients"]

Clinical Tips & Counseling

Drug interactions

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