Denosumab (Prolia) is a biologic medication used to prevent fragile bones, also known as osteoporosis, and bone fractures. As a biologic drug, it is human-made and closely resembles naturally-occurring antibodies in the body. In this case, it stops a molecule, called RANKL, which normally causes bone turnover. By blocking RANKL, it helps to strengthen bones.
Denosumab is given as an injection just under the skin. It is given by your rheumatology provider or nursing staff. The usual dose is 60 mg every six months, and it should be taken with calcium (1000 - 1200 mg daily) and vitamin D (at least 400 IU) supplementation. Denosumab works quickly - within three days of an injection, the effects on reducing bone turnover can be detected in the blood; the drug also stays in the blood for several months after stopping the medicine.
The most common side effects that patients experience are back pain, and pain in the hands and feet. The pain from denosumab can last a few days up to a few months after administration.
Denosumab can cause hypocalcium, or low calcium levels in the blood, with variable onset that is from 1-2 weeks or several months after treatment initiation.
Rarer side effects include an increased risk for atypical femur fractures (also known as stress or insufficiency fractures involving the hip joint), vertebral fractures after discontinuation of therapy, infections (especially if you’re already taking medications that lower your immune system), loss of blood supply to the jawbone (called osteonecrosis of the jaw), and severe allergic reactions.
Some symptoms may occur normally while taking denosumab, however, you should notify your rheumatology provider if you have these symptoms while taking this medication: tingling of the hands or around the mouth, new pain in the jaw, or fevers or other signs of infection.
Make sure to notify your other providers while you are taking this drug. If you are pregnant or considering pregnancy, let your provider know before starting this medication. Women should discuss birth control with their primary care providers or gynecologists. Breast-feeding should be avoided while taking denosumab because the drug can enter breast milk.
Updated February 2022 by Kristen Lee, MD, and reviewed by the American College of Rheumatology Communications and Marketing Committee.
This information provided for general education only. Individuals should consult a qualified health care provider for professional medical advice, diagnosis and treatment of a medical or health condition.