Zoledronic acid
An intravenous bisphosphonate given yearly for osteoporosis, once for Paget's disease, and more often for high calcium and bone disease in cancer.
Drug card
- Class
- Bisphosphonate
- How it works
- Binding bone mineral and blocking osteoclasts, so less bone is resorbed
- Used for
- Osteoporosis, including after a hip fracture
- High calcium caused by cancer
- Bone metastases from solid tumors
- Bone disease in multiple myeloma
- Known for
- Flu-like fever and aches in the days after an infusion
- Kidney injury, sometimes kidney failure
- Osteonecrosis of the jaw, mainly in cancer patients
- Its name
- -dronic acid, -dronate means a bisphosphonate
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does zoledronic acid work?
A third-generation bisphosphonate with an imidazole ring, given by infusion. It binds bone hydroxyapatite, inhibits farnesyl pyrophosphate synthase and drives osteoclast apoptosis, and it blocks the calcium release that factors from tumors provoke. It is not metabolized and leaves unchanged in the urine, so kidney function limits its use.
Like other bisphosphonates: Bisphosphonates are pyrophosphate analogs that bind tightly to hydroxyapatite and gather where osteoclasts are resorbing bone. Osteoclasts take them up as they work; alendronic and zoledronic acid then block farnesyl pyrophosphate synthase, so small GTPase signaling proteins go unprenylated and the cells stop resorbing or die. Bone turnover falls and bone density slowly rises.
Uses
What is zoledronic acid used for?
- Osteoporosis, including after a hip fracture
- High calcium caused by cancer
- Bone metastases from solid tumors
- Bone disease in multiple myeloma
- Paget's disease of bone
- Osteoporosis caused by glucocorticoids
Side effects
Side effects of zoledronic acid
- Flu-like fever and aches in the days after an infusionKnown for
- Kidney injury, sometimes kidney failureKnown forSerious
- Osteonecrosis of the jaw, mainly in cancer patientsKnown forSerious
- Low calcium, sometimes severeSerious
- Low magnesium and phosphate
- Atypical femur fracturesSerious
- Atrial fibrillationSerious
- Eye inflammation: uveitis, scleritis, conjunctivitisSerious
- Muscle and bone pain, sometimes severe
- Joint pain (arthralgia)
- Worse asthma in aspirin-sensitive peopleSerious
- Harm to the unborn babySerious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Contraindicated with creatinine clearance below 35 mL/min or acute kidney injury; hydrate well and check creatinine before each dose.
- Correct low calcium first and give calcium and vitamin D; loop diuretics and aminoglycosides deepen the fall in calcium.
- Have a dental check before starting and avoid invasive dental work during treatment, especially in cancer.
- Avoid in pregnancy, and never give the osteoporosis and the cancer products together: both are zoledronic acid.
Good to know: For osteoporosis one infusion covers a whole year; in cancer care it is given far more often, and osteonecrosis of the jaw is then more common.
Remember it
A way to remember it
BONES
- B
- Bone, joint and muscle pain, sometimes severe
- O
- Osteonecrosis of the jaw
- N
- Nephrotoxicity (kidney injury) with intravenous infusions
- E
- Esophagitis and ulcers from the tablets
- S
- Sit or stand upright for 30 minutes after a tablet taken with plain water
Written for biofideX
Its name
-dronic acid, -dronate means bisphosphonate
INNs end in -dronic acid (alendronic acid); US names and salts end in -dronate (alendronate). Etidronic, ibandronic and risedronic acid share it.
- Every drug name stem
Its class
Bisphosphonates
Other bisphosphonates with a card:
Easily mixed up with selective estrogen receptor modulators.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Zoledronic acid injection for osteoporosis and Paget's disease: label (DailyMed)
- Zoledronic acid injection for cancer-related bone disease: label (DailyMed)
- Zoledronic acid (NCI Thesaurus)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Thyroid, steroids and bones
Zoledronic acid is one of 9 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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