A monthly injection that builds bone and slows loss
Romosozumab
A monthly injection used for a fixed year to build bone and reduce fractures in women with severe osteoporosis.
What is Romosozumab?
Romosozumab is a specialist medicine used to treat severe osteoporosis in postmenopausal women at high risk of fractures. It is unusual in doing two things at once: it builds new bone and slows bone breakdown. It is given as an injection (usually two injections) once a month for a fixed course of 12 months only, after which another osteoporosis medicine is started. The most important safety point is that it may increase the risk of heart attack and stroke, so it is not used in people who have had a recent heart attack or stroke, and any heart risk is weighed up first.
Education and reference only. This is a plain-language guide to Romosozumab — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Romosozumab is a bone medicine used to treat severe osteoporosis in postmenopausal women who are at high risk of fractures. Osteoporosis makes bones fragile so they break easily. Romosozumab has a dual action: it both stimulates the formation of new bone and reduces the breakdown of bone, which makes it a powerful way to raise bone strength quickly. It is given as a monthly injection, usually as two injections each time, for a fixed period of 12 months, after which a different osteoporosis medicine is used to maintain the benefit. It is given under specialist supervision.
How it works
Romosozumab blocks a protein called sclerostin, which normally puts the brakes on bone formation. By removing this brake, it boosts the building of new bone, and at the same time it reduces the breakdown of bone, so bone density and strength increase markedly over the year of treatment. This dual effect is strongest in the first months and then lessens, which is part of why treatment is given as a single fixed 12-month course rather than continued. After the course, the gains are preserved by following on with another osteoporosis medicine.
Company & origin
Originated / developed by: Specialist manufacturer.
A specialist injection used in the UK to treat severe osteoporosis in postmenopausal women at high risk of fractures, given for a fixed 12-month course.
What it treats
Conditions Romosozumab is used for
Practical use
How to take Romosozumab
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given as a monthly injection, usually two injections each time, by a healthcare professional.
- It is used for a fixed course of 12 months only and is not repeated.
- Make sure any low blood calcium is corrected first, and take calcium and vitamin D as advised.
- Seek urgent help for chest pain, sudden weakness, or trouble speaking, as the heart and stroke risk matters.
- Expect to start another osteoporosis medicine after the 12 months, to keep the bone you have gained.
Weighing it up
Advantages & disadvantages of Romosozumab
Advantages
- Has a dual action, both building new bone and slowing its breakdown.
- Produces a marked increase in bone strength over a single year.
- Strongly reduces fracture risk in postmenopausal women with severe osteoporosis.
Disadvantages
- May increase the risk of heart attack and stroke, so heart risk must be assessed.
- Given as monthly injections, usually two each time, and only for a fixed 12-month course.
- Follow-on treatment is needed afterwards, and it is not repeated.
Practical use
Good to know
The most important safety message is about the heart: romosozumab may increase the risk of heart attack and stroke, so it must not be used in people who have had a heart attack or stroke in the past year, and the overall heart risk is carefully weighed before starting. You should seek urgent help for chest pain, sudden weakness or trouble speaking. Treatment is a fixed 12-month course only, given as a monthly injection (usually two injections each time), and it is not repeated; another osteoporosis medicine is started afterwards to keep the benefit, as stopping without follow-on treatment lets bone be lost. Low blood calcium should be corrected before starting, and calcium and vitamin D are usually taken alongside.
Who should not take it / use with caution
- People who have had a heart attack or stroke, particularly within the past year, should not use it.
- People with low blood calcium should not start it until the calcium is corrected.
- People who have had a serious allergic reaction to romosozumab should not use it.
Monitoring
- Assessing heart and stroke risk before starting and reviewing it during treatment.
- Checking blood calcium before and during the course, correcting it if low.
- Reviewing the response, often with a bone-density scan, and planning follow-on treatment after 12 months.
Side effects
- Joint pain, headache or injection-site reactions.
- Less commonly, low blood calcium, which is checked and corrected.
- Rarely but importantly, heart attack or stroke, so any heart or stroke symptoms need urgent attention.
Key interactions
- Calcium and vitamin D are usually taken alongside it, and low calcium is corrected first.
- Tell your team about heart and blood-pressure medicines, as overall heart risk is considered.
- Give a full list of your medicines so your specialist can weigh up the benefits and risks.
Available as: A solution for injection under the skin, usually given as two injections by a healthcare professional.
Answers
Romosozumab: frequently asked questions
What is romosozumab used for?
It is used to treat severe osteoporosis in postmenopausal women at high risk of fractures, both building new bone and slowing bone loss.
What is the main safety concern?
It may increase the risk of heart attack and stroke, so it is not used in people who have had a recent heart attack or stroke, and heart risk is assessed first.
How long is the treatment?
It is given for a fixed course of 12 months as a monthly injection, usually two injections each time, and it is not repeated.
Why do I take calcium and vitamin D with it?
Romosozumab can lower blood calcium, so calcium and vitamin D are usually taken alongside and any low calcium is corrected before starting.
What happens after 12 months?
Another osteoporosis medicine is started afterwards to keep the bone you have gained, as stopping without follow-on treatment lets bone be lost again.
Authoritative sources
- BNF
- NICE CKS
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