The benefits of bisphosphonates in postmenopausal women with osteoporosis may become evident only after one year, according to a recent meta-analysis reported in JAMA Internal Medicine.

The meta-analysis of 10 randomized clinical trials involved postmenopausal women with T scores ≤−2.5 or a vertebral fracture to determine the time to benefit of bisphosphonate use -  alendronate, risedronate and zoledronic acid – to prevent fractures. A total of 23,384 women, ages ranging from 63 to 74 years, were included in the meta-analysis.The follow up duration was 12 to 48 months.

Pooled analysis of data revealed that taking bisphosphonate for 12.4 months would reduce the risk of one nonvertebral fracture per 100 postmenopausal women at an absolute risk reduction of 0.010. By 18 months, 1.5 fractures per 100 osteoporotic postmenopausal women taking bisphosphonates were prevented.

Researchers also looked at specific fractures. To prevent one hip fracture in 200 postmenopausal women with osteoporosis, it would take 20.3 months of treatment with bisphosphonates at an absolute risk reduction of 0.005. On a similar note, 12.1 months of bisphosphonate therapy would be required to prevent one clinical vertebral fracture in 200 postmenopausal women with osteoporosis at an absolute risk reduction of 0.005.

Bisphosphonates are considered the first-line drugs for the treatment of osteoporosis in postmenopausal women. In this study, bisphosphonates were beneficial when used for a longer period of time. However, potential adverse effects may occur even with short-term use such as upper gastrointestinal irritation and musculoskeletal pain (which may be severe enough to necessitate discontinuation of the drug). These have to be weighed in with the benefits of long-term use. Treatment therefore must be individualized and based on the patients preference.

Reference

1. Deardorff WJ, et al. Time to benefit of bisphosphonate therapy for the prevention of fractures among postmenopausal women with osteoporosis: a meta-analysis of randomized clinical trials. JAMA Intern Med. 2021 Nov 22;e216745. doi: 10.1001/jamainternmed.2021.6745.