Ibandronic acid
Bisphosphonates
Bisphosphonates
A nitrogen-containing bisphosphonate taken by mouth or given into a vein. It slows bone loss in postmenopausal osteoporosis.
Also called: Ibandronate
Quick facts
- Group
- Bisphosphonates
- Target
- Farnesyl pyrophosphate synthase (FPPS) in osteoclasts
- Used for
- Treatment and prevention
- Key effects
- Heartburn · Headache and dizziness · Bone
- Monitor
- Serum calcium · Kidney function · Dental health before
- ATC
- M05BA06
No doses: the clinician sets them by the current guideline.
Mechanism of action
The figure shows ibandronate itself in the active site of human farnesyl pyrophosphate synthase (crystal structure).
Ibandronic acid binds bone mineral and is taken up by osteoclasts as they resorb bone. Inside the osteoclast it inhibits farnesyl pyrophosphate synthase in the mevalonate pathway, so small GTPases cannot be prenylated; the osteoclast loses its resorbing function and dies. Bone breakdown slows and bone density increases.
- Ibandronate binds bone mineral at resorption sites
- Osteoclasts take it up while resorbing bone
- FPPS inhibition blocks protein prenylation
- Osteoclasts stop working; bone loss slows
Indications
- Treatment and prevention of osteoporosis in postmenopausal women Osteoporosis →
Adverse effects
Common
- Heartburn, nausea, abdominal pain, diarrhoea or constipation
- Headache and dizziness
- Bone, muscle or joint pain
- Flu-like symptoms after the first intravenous dose
Contraindications
- Hypocalcaemia not corrected
- For tablets: inability to stand or sit upright for 60 minutes, or oesophageal disorders that delay emptying
- Caution: kidney disease
Key interactions
- Calcium, antacids, iron, vitamins and other oral medicines
- Block absorption; they are taken at least 60 minutes after the tablet
- Aspirin and NSAIDs
- More stomach and oesophageal irritation
What is monitored
- Serum calcium and vitamin D before starting
- Kidney function
- Dental health before and during treatment
- Bone mineral density
Administration and safety
- Tablet: first thing in the morning on an empty stomach, swallowed whole with plain water only
- The person stays upright and takes no food, drink or other medicine for 60 minutes
- Injection: into a vein by a health professional, every 3 months and not more often
Pregnancy and breastfeeding
It is used after menopause. It stays in bone for years, so future pregnancy plans are discussed before use in younger people.
Nursing care
- Teach the tablet routine exactly; errors cause oesophagitis or no absorption
- Ask about heartburn, painful swallowing or chest pain
- Encourage a dental check and good oral hygiene
- Encourage adequate calcium and vitamin D
- Ask about new thigh or groin pain
Pharmacokinetics
- Absorption
- Very poor by mouth and blocked by food, drinks other than plain water, and minerals; also given intravenously
- Distribution
- Binds bone and stays there for years
Test yourself
Think of the answer, then tap the question to see it.
Which enzyme do nitrogen-containing bisphosphonates such as ibandronate inhibit?
Farnesyl pyrophosphate synthase in the osteoclast mevalonate pathway, which blocks prenylation of small GTPases.
Why must ibandronate tablets be taken with plain water and the person stay upright for 60 minutes?
Food, drinks and minerals block its tiny absorption, and lying down lets it irritate the oesophagus.
Which rare jaw and femur complications are shared by bisphosphonates?
Osteonecrosis of the jaw and atypical femoral fracture.
Connections
← Back to the class: Bisphosphonates
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Ibandronate: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); Ibandronate Injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.