What FRAX (Fracture Risk Assessment Tool) scores require prescription medications like bisphosphonates (e.g. alendronate, risedronate), denosumab, or teriparatide?

FRAX Scores That Require Prescription Medications for Osteoporosis

Prescription medications for osteoporosis are recommended when the FRAX 10-year risk is ≥20% for major osteoporotic fracture or ≥3% for hip fracture, or when the BMD T-score is ≤-2.5. 1

Risk Assessment Categories

FRAX scores are categorized into risk groups that guide treatment decisions:

• Low Risk: BMD T-score >-2.5 AND FRAX 10-year risk of major osteoporotic fracture <20% AND hip fracture <3%
• High Risk: BMD T-score ≤-2.5 but >-3.5 OR FRAX 10-year risk of major osteoporotic fracture ≥20% but <30% OR hip fracture ≥3% but <4.5%
• Very High Risk: Prior osteoporotic fracture OR BMD T-score ≤-3.5 OR FRAX 10-year risk of major osteoporotic fracture ≥30% OR hip fracture ≥4.5% 1

Special Considerations for FRAX Calculation

When using FRAX to calculate fracture risk, important adjustments may be needed:

• For patients on glucocorticoids, increase the calculated risk of major osteoporotic fracture by 1.15 and hip fracture by 1.2 2, 1
• For patients on high-dose glucocorticoids (>7.5 mg/day prednisolone), multiply hip fracture risk by 1.2 and major osteoporotic fracture risk by 1.15 2
• For patients on low-dose glucocorticoids (<2.5 mg/day), multiply hip fracture risk by 0.65 and major osteoporotic fracture risk by 0.8 2

Treatment Recommendations Based on Risk

High-Risk Patients

For patients with high fracture risk (FRAX ≥20% for major osteoporotic fracture or ≥3% for hip fracture):

• First-line treatment: Oral bisphosphonates (alendronate or risedronate) 1
• Alternatives if oral bisphosphonates are contraindicated:
  • IV bisphosphonate (zoledronic acid)
  • Denosumab (especially for those with renal impairment) 1

Very High-Risk Patients

For patients with very high fracture risk (prior fracture, T-score ≤-3.5, FRAX ≥30% for major osteoporotic fracture or ≥4.5% for hip fracture):

• Consider anabolic agents first (teriparatide, abaloparatide, or romosozumab) followed by an antiresorptive agent 1, 3
• Romosozumab is limited to 12 monthly doses, after which transition to an antiresorptive agent is recommended 1
• Teriparatide and abaloparatide are limited to 2 years of treatment due to safety concerns 1

Additional Considerations

• In patients with inflammatory bowel disease, the high-risk threshold for intervention is a T-score of -1.5 or a FRAX 10-year risk of 20% for major osteoporotic fracture 2
• For adults under 40 years of age with a history of osteoporotic fracture or those on long-term glucocorticoids (≥7.5 mg/day for ≥6 months) with a hip or spine BMD Z-score <-3 or bone loss ≥10%/year, oral bisphosphonates should be considered 2
• All patients should receive calcium (1,000-1,200 mg/day) and vitamin D (600-800 IU/day; serum level ≥20 ng/ml) supplementation 2, 1
• Lifestyle modifications including weight-bearing exercise, maintaining healthy weight, smoking cessation, and limiting alcohol intake are important adjuncts to pharmacological therapy 2, 1

Monitoring and Follow-up

• BMD testing should be done every 1-3 years, with earlier reassessment (within 1 year) for patients on high-dose glucocorticoids or with prior fractures 1
• After 5 years of bisphosphonate therapy, reevaluate fracture risk to determine whether to continue or discontinue treatment 1

By following these evidence-based guidelines for FRAX score interpretation and treatment initiation, clinicians can effectively identify and treat patients at risk for osteoporotic fractures, thereby reducing morbidity and mortality associated with these fractures.