Who Is a Candidate for Abaloparatide? General Indications
Abaloparatide (Tymlos) is an anabolic agent used to build new bone, primarily in individuals with severe osteoporosis at high risk for fractures. This includes postmenopausal women and men. High risk may be defined by factors such as a history of fracture, multiple fracture risk factors, or insufficient response to other osteoporosis treatments.
Eligibility for Postmenopausal Women
For postmenopausal women, abaloparatide is indicated for osteoporosis treatment to reduce vertebral and nonvertebral fractures. Candidates may have very low bone mineral density, a history of fragility fractures, or have not improved with other therapies.
Eligibility for Men with Osteoporosis
Abaloparatide is also approved for men with osteoporosis at high risk of fracture. Eligibility criteria are similar to women, focusing on fracture history, multiple risk factors, or inadequate response to other treatments. Studies have shown increased BMD in men treated with abaloparatide.
Contraindications: Who Cannot Take Abaloparatide?
Certain conditions make abaloparatide unsafe due to a black box warning about the risk of osteosarcoma, a rare bone cancer, observed in animal studies. Contraindications include:
- History of bone cancer or skeletal malignancies.
- Paget's disease of the bone.
- Unexplained elevated alkaline phosphatase levels.
- Pediatric patients with open epiphyses.
- History of radiation therapy involving the skeleton.
- Primary hyperparathyroidism or chronic hypercalcemia.
- Hypersensitivity to abaloparatide or its components.
- Pregnant or breastfeeding women.
Precautions and Important Safety Considerations
Even in eligible patients, precautions are necessary:
Orthostatic Hypotension
A sudden drop in blood pressure upon standing, causing dizziness, is a common side effect. It is recommended to administer initial doses while sitting or lying down.
Hypercalciuria and Urolithiasis
Abaloparatide can increase urinary calcium, raising the risk of kidney stones. Monitoring calcium levels may be needed, especially for those with a history of kidney stones.
Supplementation
Adequate calcium and vitamin D intake are crucial and should be discussed with a doctor.
Limited Treatment Duration
Treatment is typically limited to a total of two years due to concerns about the long-term risk of osteosarcoma seen in animal studies. A subsequent medication, often an antiresorptive agent, is usually prescribed to maintain bone density gains.
Comparing Abaloparatide with Teriparatide
Abaloparatide and teriparatide (Forteo) are both bone-building agents targeting the parathyroid hormone 1 receptor, but with subtle differences in their action.
| Feature | Abaloparatide (Tymlos) | Teriparatide (Forteo) |
|---|---|---|
| Mechanism | Synthetic analog of PTHrP with selective activation of PTH1R. | Recombinant human PTH stimulating bone formation and resorption. |
| Indications | Postmenopausal women and men with osteoporosis at high risk of fracture. | Postmenopausal women and men with osteoporosis at high risk of fracture. |
| Efficacy | Significant increase in BMD, potentially greater in hip density. | Effective in increasing BMD and reducing fracture risk. |
| Side Effects | Common: injection site reactions, dizziness, nausea. Possibly fewer discontinuations than teriparatide. | Common: nausea, leg cramps, dizziness. |
| Use Limit | Up to 2 years of lifetime use. | Up to 2 years of lifetime use. |
Conclusion
Abaloparatide is a significant treatment for postmenopausal women and men with severe osteoporosis at high risk of fracture. Eligibility is based on medical history, fracture risk, and response to previous treatments, with strict contraindications related to bone cancer risk. Treatment is limited to two years and requires monitoring for side effects. Decisions about abaloparatide should be made in consultation with a healthcare provider. For more information on bone health, consult resources like the {Link: NIH.gov https://www.nih.gov}.
