Zoledronic acid

Easy-to-read medicine information about zoledronate– what it is, how to take zoledronate safely and possible side effects. Zoledronate is also called Aclasta or Zometa.

Type of medicine Also called
  • Belongs to a group of medicines known as bisphosphonates, which are used to treat bone disease.
  • Aclasta®
  • Zometa®

What is zoledronate?

  • Zoledronate used to treat bone disease such as osteoporosis and Paget's disease. 
    • Osteoporosis is a condition that causes your bones to be thinner and weaker than normal. This means that they can break (fracture) easily, such as after a small bump or fall. In osteoporosis zoledronate prevent bone loss, increase bone thickness and lower your risk of spine and hip fractures. For the treatment of osteoporosis, zoledronate injection is used if the tablet forms of bisphosphonates are unsuitable for you.  
    • In Paget's disease the abnormal bone growth causes deformity and pain. Zoledronate can help with this.
  • Zoledronate may also be used to reduce the high levels of calcium in the blood (called hypercalcaemia) which can happen with some cancers.
  • Zoledronate is given by injection, as a drip into the vein. It belongs to a group of medicines called bisphosphonates.

Watch a video about zoledronate for the treatment of osteoporosis:

(RheumInfo, 2019)

How is zoledronate given?

  • Zoledronate is given by intravenous infusion or 'drip', so medication is injected into the vein in the arm and drips in slowly over 15 to 30 minutes.  
  • The number of doses you will be given will depend upon why it has been prescribed for you. Many people need only a single dose. Extra doses may be needed for people with osteoporosis and in some cancers.
  • Zoledronate infusion can be given to you by your GP or you may be referred to a specialist or clinic.

Special instructions

  • Blood tests: before having zoledronate infusion, you will need blood tests to check the calcium levels in your blood and how well your kidneys are working. 
  • Avoid dehydration: it is important that you do not become dehydrated during treatment with zoledronate. Your doctor will advise how much water you need to drink – this is usually one or two large glassfuls before and after treatment.
  • Calcium and vitamin D: for zoledronate to work, you may need to take vitamin D (also called colecalciferol) supplements and ensure that you have enough calcium in your diet.

Precautions before having zoledronate

  • Do you have a heart condition?
  • Are you planning to have any dental treatment in the near future?
  • Do you have any problems with the way your kidney or liver works?
  • Are pregnant or breastfeeding?
  • Are you taking any other medicine (including over-the-counter and herbal products)?

If so, it’s important that you tell your doctor before you start having zoledronate. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

What are the side effects of zoledronic acid?

Like all medicines zoledronate can cause side effects, although not everyone gets them.

Problems with your jaw

Zoledronate can cause osteonecrosis of the jaw, which is a problem with the jaw, that can be caused by delayed healing in the mouth after some dental procedures. This is quite rare. To reduce the risk of this problem, it is best to:

  • Take good care of your teeth and mouth (such as brushing your teeth twice a day and regular flossing between your teeth).
  • Have regular dental check-ups.
  • If you need any dental treatment, it is best that you have this done before you start treatment with zoledronate.
  • Let your dentist know that you are having zoledronate treatment.
  • Talk to your doctor or dentist if you have any loose teeth, tooth pain, or swelling or numbness in your jaw.

Other side effects

Side effects What to do
  • Flu-like symptoms such as muscle and joint pains, fever, headache
  • Irritation or burning at the site of the injection 
  • These symptoms are quite common with zoledronate injection. They tend to go away after a few days.
  • Your doctor can recommend a mild pain reliever such as paracetamol to reduce these side effects. 
  • Tell your doctor if troublesome
  • Eye pain
  • Red eye
  • Changes in your vision
  • Sensitive to light
  • Floating spots in your vision
  • These symptoms are related to inflammation in the eye. This is quite rare.³
  • Contact your doctor immediately if you experience these symptoms. 
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product

Learn more

The following links provide further information on zoledronate. Be aware that websites from other countries may contain information that differs from New Zealand recommendations.

Zoledronate Rheuminfo
Zoledronic acid (for cancer patients)
New Zealand Formulary Patient Information
Zoledronic acid (for osteoporosis) New Zealand Formulary Patient Information
Aclasta Medsafe Consumer Information (NZ)
Zometa Medsafe Consumer Information (NZ)

Zoledronic acid (Aclasta)
National Osteoporosis Society, UK
Bisphosphonates (intravenous/IV) Australian Rheumatology Association


  1. Osteonecrosis: A Pain in the Jaw Medsafe Prescriber Update 33(2): 13-14 June 2012
  2. Osteonecrosis Of The Jaw And Bisphosphonates - Putting The Risk In Perspective Medsafe Publications, October 2007
  3. Reminder: Keeping an eye on bisphosphonates Medsafe Prescriber Update 32(3): 24 September 2011
  4. An update on bisphosphonates BPAC, November 2014
  5. Zoledronic acid New Zealand Formulary 
  6. Zometa Medsafe Datasheet
  7. Aclasta Medsafe Datasheet

Additional resources for healthcare professionals

Bisphosphonates NZ Formulary
Zoledronic acid – safe prescribing - bone up SafeRx, NZ, 2015

Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 18 Apr 2017