Forsteo

Forsteo is the brand name for teriparatide, a recombinant form of parathyroid hormone consisting of the first 34 amino acids (PTH 1-34). It is an anabolic osteoporosis medication that, when given as intermittent subcutaneous injections, stimulates osteoblast activity more than osteoclast activity, leading to increased bone formation and higher bone mineral density. In clinical use, it reduces the risk of vertebral and nonvertebral fractures in adults with osteoporosis.

Indications include osteoporosis in adults at high risk of fracture, such as postmenopausal women and men with established osteoporosis, and glucocorticoid-induced osteoporosis in adults at high fracture risk. Forsteo is typically used for a limited duration, with a common guideline of up to 2 years of lifetime treatment.

Dosing and administration involve 20 micrograms by subcutaneous injection once daily, usually in the thigh or abdomen, with rotation of injection sites. After completing Forsteo therapy, patients are generally transitioned to an antiresorptive agent to help maintain gains in bone density.

Contraindications and precautions include hypercalcemia, pre-existing bone malignancies or metastases, Paget disease of bone, unexplained elevations of alkaline phosphatase, and skeletal conditions associated with high osteosarcoma risk. The drug is not recommended during pregnancy or breastfeeding. A boxed warning notes osteosarcoma risk observed in rat studies; the relevance to humans is uncertain but informs risk assessment. Common adverse effects are nausea, leg cramps, dizziness, injection-site reactions, and transient orthostatic symptoms.

Forsteo was developed by Eli Lilly and was approved by the U.S. FDA in the early 2000s for osteoporosis treatment.