What precautions should be considered prior to prescribing teriparatide or abaloparatide?
• Teriparatide and abaloparatide are contraindicated in patients at increased risk for osteosarcomas: Paget’s disease, unexplained alkaline phosphatase elevation, children and young adults with open epiphyses, prior external beam or implant radiation therapy involving the skeleton.
• In patients without contraindications, teriparatide does not cause an increased risk of osteosarcomas compared with the general population (1: 250,000). Data on osteosarcoma in adults on long-term abaloparatide therapy is not yet available.
• Use in patients with skeletal metastases and myeloma is contraindicated.
• May cause hypercalcemia (digoxin toxicity, kidney stones) and hyperuricemia (gout).
• Expensive. They are cost-effective when used in patients at highest risk for osteoporotic fractures (T score <–2.5 to –3.0 with history of fragility fracture; T score ≤–3.0) or in patients who develop a fragility fracture while on an oral bisphosphonate.
• Teriparatide and abaloparatide can help heal stress fractures (especially sacral, pelvic), nonunion fractures, and ONJ. However, this is not an FDA-approved use for these agents.
• Teriparatide and abaloparatide should not be used concurrently with an antiresorptive agent. Blunting of the anabolic response has been demonstrated in patients who have previously received prolonged alendronate therapy prior to starting teriparatide. This blunting has not been apparent when teriparatide was used concurrently with zoledronic acid or denosumab in patients who have not received previous bisphosphonate or denosumab therapy. However, fracture reduction efficacy has not yet been demonstrated with combination therapy.
• The PTH level should be checked prior to using anabolic bone drugs. If elevated, secondary causes (vitamin D deficiency) should be corrected to normalize the PTH level. The benefit of teriparatide and abaloparatide in patients with persistent mild elevations of PTH (<150 pg/mL) is unclear, but many experts feel it can still be effective. It can be used in patients with severe kidney disease, but the effectiveness in these patients (who frequently have an elevated PTH) is unknown.
• After treatment with teriparatide or abaloparatide, an antiresorptive agent should be started to preserve the gains in bone mass. Otherwise, bone mass declines significantly after these agents are stopped.
• After one 2-year course of teriparatide, a subsequent course in patients with severe osteoporosis is presently being studied (intermittent osteoanabolic therapy).
