Zoledronic Acid


What is Zoledronic Acid and how does it work?

Zoledronic Acid is used for;

  • A bone disease called Paget’s disease 
  • Osteoporosis in postmenopausal women at high risk of breaking a bone
  • Osteoporosis in men at high-risk breaking a bone 
  • Osteoporosis caused by long-term treatment with corticosteroids 

This is a type of medicine called a bisphosphonate. Bisphosphonates are medicine that reduces the turnover of bone. The bone is continually shaped and not a static structure. It is also reformed and rebuilds by cells called osteoblasts. These cells continuously deposit and remove calcium and phosphorus that is stored in a protein network that makes up the structure of the bone. 

In Paget’s disease of bone, the normal metabolism of bone is disturbed. There is an increase in the bone breakdown by the osteoclasts and increased and irregular formation of new bone by the osteoblasts. The normal bone marrow also becomes replaced with blood vessels and fibrous tissue. In this disease, there are often no symptoms for many years. But, over time the bones can become painful, enlarged, weak, deformed, and prone to breaking. The enlarged and deformed bones can also put pressure on nerves which causes pain and muscle weakness.

In postmenopausal women, blood levels of the female hormone estrogen start to decrease. This results in an increase in the bone breakdown by the osteoclasts that may lead to a loss of bone density. Bone loss is particularly rapid for the first ten years after menopause and it may lead to the development of osteoporosis. 

Zoledronic Acid works by binding very tightly to the bone and preventing the calcium from being removed by the osteoclasts. This stops the osteoclasts from breaking down the bone. The reduced bone turnover helps to reduce deformity and keep the bones strong and less likely to break. 

How to use Zoledronic Acid?

This is given by injection into a vein as directed by your doctor. It is usually given over at least 15 minutes. The dosage is based on your medical condition and response to the treatment. Before using, check the drug visually for discoloration or particles. You should not use the liquid if either is present. 

As this medicine slows bone turnover and so prevents calcium from being reabsorbed from the bones into the blood, it can cause the amount of calcium in your blood to fall too low. Your doctor may ask you to take calcium and vitamin D supplements before you have your infusion and if you have Paget’s disease. It may be for at least ten days after it to prevent this.

What are the side effects of Zoledronic Acid?

  • Headache
  • Dizziness
  • Vision problems
  • Cough
  • Tried feeling
  • Constipation 
  • Joint or muscle pain
  • Redness or swelling where the needle was placed  
  • Flu-like symptoms (muscle or joint aches, chills, and fever)


  • If you have recently broken your hip, it is recommended that this medicine is not given until at least two weeks after hip is fully repaired. 
  • Your doctor will want you to have blood tests before you have this medication. It is to check the level of calcium in your blood. 
  • Your doctor will also want to check your kidney function before each dose of this drug. This is important if you have any existing problems or if you are also taking diuretics or other drugs that can affect the kidneys. 
  • You must drink enough fluid both before and after infusion to prevent dehydration. 
  • This is not recommended for use in people who are allergic to Zoledronic Acid.