When to Start Anabolic Agents for Osteoporosis According to Osteoporosis Canada Guidelines
Anabolic agents such as teriparatide should be used only in patients with very high risk of fracture, followed by bisphosphonate therapy to maintain bone density gains. 1
Patient Selection for Anabolic Therapy
Anabolic agents are reserved for specific high-risk populations:
- Very high fracture risk patients, defined as:
- Older age (typically >74 years)
- Recent fracture (within past 12 months)
- History of multiple clinical osteoporotic fractures
- Multiple risk factors for fracture
- Failure of other available osteoporosis therapies 1
Specific Indications for Teriparatide
Teriparatide (recombinant parathyroid hormone 1-34) should be considered for:
- Postmenopausal women with severe osteoporosis
- Men with severe idiopathic or hypogonadal osteoporosis
- Patients with established glucocorticoid-induced osteoporosis requiring long-term steroid treatment
- Individuals younger than 65 years with particularly low bone mineral density (T-scores ≤ -3.5) 2
Efficacy of Anabolic Therapy
Teriparatide has demonstrated significant benefits in high-risk populations:
- Reduces risk for any clinical fractures (27 fewer events per 1000 patients)
- Reduces radiographic vertebral fractures (69 fewer events per 1000 patients)
- May reduce clinical vertebral fractures (45 fewer events per 1000 patients) 1
When compared to bisphosphonates:
- Probably reduces risk for radiographic vertebral fractures (66 fewer events per 1000 patients)
- May reduce risk for any clinical fracture (46 fewer events per 1000 patients) 1
Treatment Duration and Follow-up
- Teriparatide therapy is limited to a maximum of 2 years 2
- After completing teriparatide treatment, patients should transition to an antiresorptive agent to maintain bone density gains 3
- Failure to follow teriparatide with antiresorptive therapy will result in rapid bone loss and increased fracture risk 1, 3
Contraindications and Precautions
Teriparatide is contraindicated in:
- Patients with increased baseline risk of osteosarcoma
- Those with Paget's disease of bone
- Patients with open epiphyses
- Patients with prior radiation therapy involving the skeleton 1
- Patients with bone metastases, including those who may have micrometastatic or occult disease 1
Adverse Effects
Common adverse effects include:
- Nausea, dizziness, vomiting, headache, palpitations, and leg cramps 1
- Increased risk of withdrawal due to adverse effects (17-127 more events per 1000 patients) 1
Important Clinical Considerations
- Daily calcium intake should be limited to 1500 mg with adequate vitamin D (≤1000 U/day) 2
- Monitor serum calcium after 1 month of treatment 2
- Concurrent therapy with antiresorptive agents, particularly bisphosphonates, should be avoided 2
- Sequential therapy with antiresorptive agents after teriparatide is essential to maintain benefits 3
Alternative Anabolic Options
Besides teriparatide, other anabolic options include: