Pamidronic acid
Bisphosphonates
Bisphosphonates
An intravenous bisphosphonate. It lowers high calcium from cancer and protects bone in myeloma, bone metastases and Paget's disease.
Also called: Pamidronate
Quick facts
- Group
- Bisphosphonates
- Target
- Farnesyl pyrophosphate synthase (FPPS) in osteoclasts
- Used for
- Hypercalcaemia of malignancy · Paget's disease of bone
- Key effects
- Redness · Nausea · Bone
- Monitor
- Serum calcium · Kidney function · Dental health
- ATC
- M05BA03
No doses: the clinician sets them by the current guideline.
Mechanism of action
The figure shows pamidronate itself in the active site of human farnesyl pyrophosphate synthase (crystal structure).
Pamidronic acid binds bone mineral and is taken up by resorbing osteoclasts, where it inhibits farnesyl pyrophosphate synthase. Osteoclasts stop resorbing bone, so less calcium is released into the blood and bone destruction by tumours or Paget's disease slows.
- Pamidronate binds bone at sites of high turnover
- Osteoclasts take it up and FPPS is inhibited
- Bone resorption falls
- Less calcium leaves bone; serum calcium falls
Indications
- Hypercalcaemia of malignancy Hypercalcaemia of malignancy →
- Bone lesions of multiple myeloma, with chemotherapy Multiple myeloma →
- Bone metastases of breast cancer, with chemotherapy Breast cancer →
- Paget's disease of bone Paget disease of bone →
Adverse effects
Common
- Fever and flu-like symptoms after the first infusion, which usually do not recur
- Redness, swelling or pain at the infusion site
- Nausea, vomiting, abdominal pain, constipation or diarrhoea
- Bone, muscle or joint pain
- Headache, tiredness and swelling of the legs
Contraindications
- Hypersensitivity to pamidronate or other bisphosphonates
- Caution: kidney disease
Key interactions
- Calcium and vitamin D supplements
- Often recommended alongside to prevent low calcium
- Chemotherapy for myeloma or breast cancer
- Given together for bone protection
What is monitored
- Serum calcium, phosphate and magnesium
- Kidney function (creatinine) before each dose
- Dental health
- Temperature after the first infusion
Administration and safety
- Intravenous only, as a slow infusion over hours, never as a rapid injection
- Faster or more concentrated infusions cause more reactions
- Kidney function is checked before each dose
- A dental examination comes before starting when possible
Pregnancy and breastfeeding
It may stay in the body for years and could affect a fetus; reliable contraception is used and the prescriber is told about pregnancy plans.
Nursing care
- Check creatinine and calcium before the infusion
- Warn about fever and aches after the first infusion
- Inspect the infusion site
- Teach the signs of low calcium and of jaw problems
- Advise reliable contraception in people who could become pregnant
Pharmacokinetics
- Absorption
- Given only intravenously, as a slow infusion over several hours
- Distribution
- Binds bone and can stay in the body for years
Test yourself
Think of the answer, then tap the question to see it.
How does pamidronate lower calcium in hypercalcaemia of malignancy?
It inhibits osteoclast bone resorption, so less calcium is released from bone.
What reaction is typical after the first pamidronate infusion?
A short-lived acute-phase reaction: fever, flu-like symptoms and muscle or joint aches.
Which laboratory value is checked before each pamidronate infusion for safety?
Kidney function (serum creatinine), together with calcium.
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: Pamidronate 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.