Glucocorticoid-induced osteoporosis

Glucocorticoids can reduce bone mineral density (BMD) in both men and women. They reduce bone formation and increase bone resorption by reducing osteoblast function and intestinal calcium absorption, and causing osteocyte dysfunction, hypercalciuria and gonadal suppression. Glucocorticoids also increase fracture risk independent of BMD, so a patient taking a glucocorticoid has a higher fracture risk than a patient not taking a glucocorticoid who has the same BMD.

The highest rate of bone loss occurs within the first 3 to 6 months of treatment; a slower decline continues with ongoing use. The extent of bone loss is related to the dose and the duration of glucocorticoid therapy. A prednisolone (or prednisone) dose of at least 7.5 mg per day, or an equivalent dose of another glucocorticoid (see Approximate relative potency and duration of effect of glucocorticoids), is associated with the greatest risk. However, an increase in bone loss and fracture risk has been observed with prednisolone (and prednisone) doses as low as 2.5 mg daily.

Before starting glucocorticoid therapy that is expected to continue long term, assess the patient’s risk of fracture, and measure their BMD. For all patients, ensure their calcium intake is sufficient and they are vitamin D replete. Also optimise the management of any other risk factors for fracture (see Risk factors for minimal-trauma fracture), and provide advice on prevention of minimal-trauma fracture.

In patients who will receive at least 7.5 mg prednisolone (or prednisone) per day (or an equivalent dose of another glucocorticoid [see Approximate relative potency and duration of effect of glucocorticoids]) for at least 3 months, and who have a baseline T-score lower than –1.5, consider drug therapy to prevent glucocorticoid-induced osteoporosis. Clinical judgement is necessary when assessing fracture risk; in addition to baseline BMD and glucocorticoid dose, factors such as patient age and comorbidities affect the decision to treat and choice of therapy.

Bisphosphonates prevent fractures in patients taking glucocorticoid therapy, and are considered first-line treatment. Denosumab can also prevent fracture in these patients, but at the time of writing it is not available on the Pharmaceutical Benefits Scheme (PBS) for this indication¹. Teriparatide is more effective than alendronate in reducing vertebral fractures in patients taking glucocorticoids, but strict eligibility criteria for PBS funding apply². Estrogen therapy can prevent or reduce glucocorticoid-induced bone loss in postmenopausal women.

If no other risk factors are present, preventive drug therapy may only be required for the duration of glucocorticoid treatment.

Consider measuring BMD every 12 to 24 months for the first few years of glucocorticoid treatment. If BMD results are stable and acceptable, further BMD measurement can be less frequent.

¹ See the Pharmaceutical Benefits Scheme website for current information on eligibility criteria for denosumab.Return

² See the Pharmaceutical Benefits Scheme website for current information on eligibility criteria for teriparatide.Return