Injectable Osteoporosis Medications for High-Risk Patients with Fall Risk
The primary injectable medications for osteoporosis patients at high risk with fall risk are denosumab (subcutaneous, every 6 months) and teriparatide (subcutaneous, daily), with denosumab being the most commonly used "shot" given every 6 months. 1, 2, 3
Denosumab (Prolia®)
Denosumab is administered as a 60 mg subcutaneous injection every 6 months and is specifically approved for patients with osteoporosis at high risk for fracture. 3, 4
- This fully human monoclonal antibody targets RANKL, inhibiting osteoclast formation and bone resorption 3, 5
- Reduces vertebral fractures by approximately 70%, nonvertebral fractures, and hip fractures in high-risk patients 6, 4
- Particularly valuable for patients with impaired renal function or intolerance to oral bisphosphonates 4
- The American College of Rheumatology conditionally recommends denosumab for adults ≥40 years at high fracture risk 7
Critical Safety Consideration for Denosumab
After discontinuing denosumab, patients must transition to another antiresorptive agent to prevent rebound bone loss and increased risk of multiple vertebral fractures. 1, 3, 5
- Stopping denosumab causes rapidly rising bone turnover markers and decreasing bone density 3
- Risk of multiple vertebral fractures increases after discontinuation 5, 8
- Sequential therapy with bisphosphonates is essential after stopping denosumab 1
Teriparatide (Forteo®)
Teriparatide is a daily subcutaneous injection (anabolic agent) that is conditionally recommended over antiresorptive agents for patients at very high fracture risk. 7, 2
- FDA-approved for postmenopausal women and men with osteoporosis at high risk for fracture, including those on chronic glucocorticoid therapy 2
- The American College of Rheumatology conditionally recommends PTH/PTHrP agents (like teriparatide) over antiresorptive agents in very high-risk patients 7, 1
- Particularly indicated for patients with prior osteoporotic fractures, multiple risk factors, or who have failed other therapies 2
- Requires sequential therapy with an antiresorptive agent after completion to maintain bone gains 1
Intravenous Zoledronic Acid
Zoledronic acid 5 mg given as a single yearly 15-minute infusion is another injectable option that reduces vertebral fractures by 70% over 3 years. 7
- Administered annually rather than every 6 months like denosumab 7
- Conditionally recommended by the American College of Rheumatology for moderate, high, and very high-risk patients 7
Risk Stratification for High-Risk Patients
Very high fracture risk is defined as prior osteoporotic fracture(s), BMD T-score ≤-3.5, FRAX 10-year risk of major osteoporotic fracture ≥30% or hip ≥4.5%, or high-dose glucocorticoids (≥30 mg/day for >30 days). 7, 1
- High fall risk patients should be specifically evaluated for fracture risk using FRAX (adjusted for glucocorticoid use if applicable) and BMD testing 7, 1
- For glucocorticoid users taking >7.5 mg/day prednisone, multiply FRAX major osteoporotic fracture risk by 1.15 and hip fracture risk by 1.2 7, 1
Common Pitfalls to Avoid
- Never discontinue denosumab without transitioning to another antiresorptive agent due to rebound bone loss and vertebral fracture risk 1, 3, 5
- Failing to assess for asymptomatic vertebral fractures with VFA or spine x-rays, which significantly increase future fracture risk 1
- Not considering anabolic agents (teriparatide) first in very high-risk patients before antiresorptive therapy 7, 1
- Overlooking the need for adequate calcium (1000-1200 mg/day) and vitamin D (600-800 IU/day) supplementation with all osteoporosis treatments 7, 1, 6