On denosumab or zoledronic acid: what to know

This page is for people already having denosumab injections or a yearly zoledronic acid drip for osteoporosis, which means weak, thin bones. Both are bone-saving medicines. Please do not stop, delay or switch either one on your own. Your doctor will plan any change with you.

The page is for men and women. Most of the trial numbers below come from studies in women after menopause, and the page says so next to each one. Trials in men are fewer and smaller, and all were outside India. In a 2-year trial of 1,199 men, new spine fractures on X-ray were 1.6 in 100 with zoledronic acid, against 4.9 in 100 on a dummy treatment. In a 3-year trial of men on hormone treatment for prostate cancer, new spine fractures were 1.5 in 100 with denosumab, against 3.9 in 100. If you are a man on one of these medicines, ask your doctor how the results apply to you.

How does denosumab work?

Denosumab is an injection given every 6 months. It blocks the signal that makes bone-removing cells work. A large trial in women after menopause found fewer spine and hip fractures with it. Its effect wears off quickly once the doses stop.

Can I stop denosumab?

Not without a plan from your doctor. In one large study of women after menopause, those who stopped with no follow-on medicine had many more spine fractures. The yearly rate rose from 1.2 to 7.1 per 100 people, and many had more than one fracture at once.

Doctors usually plan another bone medicine, often zoledronic acid, about 6 months after the last injection.

What if my injection is late?

Speak to your doctor soon. Studies show that bone breakdown rises above normal within about 6 months of a missed dose.

I have been on denosumab for many years. Is stopping harder?

It can be. In one small European study, people had taken denosumab for about 4.6 years. One dose of zoledronic acid after that did not fully stop bone loss. In another small European study, people who had more than 6 injections lost more bone after stopping than people who had 6 or fewer. Doctors may check bone density and blood markers, and they may advise more than one dose.

How does zoledronic acid work?

Zoledronic acid is a bisphosphonate, a type of bone-saving medicine. For osteoporosis, it is given as a drip once a year. It sticks to bone and slows the cells that remove bone. A large trial in women after menopause found 70% fewer spine fractures over 3 years with it. It stays in bone for years, so its effect fades slowly.

Can I take a break from bisphosphonates?

Do not stop on your own. Some people ask about a drug holiday, which means a planned break from the medicine. The UK guideline says routine drug holidays are not supported. Women who stayed on alendronate after 5 years, or on zoledronic acid after 3 years, had fewer spine fractures than women who stopped. Your doctor reviews this with you using a scan and a risk check.

Related guides

• Bone builders and bone savers
• DEXA scan explained

For doctors

The evidence behind this page is in Sequential vs combination osteoporosis therapy, How osteoporosis drugs work and Osteoporosis questions and evidence answers.

Talking to a doctor in Patiala

To talk about your bone medicine plan with Dr Aditya Aggarwal, orthopaedic surgeon, call Aggarwal Clinic on +91 98768 24676.

Aggarwal Clinic, 1-E, The Mall, Patiala.

This page is general information, not medical advice. Please talk to your doctor about what is right for you.