teriparatide

Teriparatide is a recombinant form of parathyroid hormone consisting of the first 34 amino acids of the native hormone (PTH 1-34). It acts as an osteoanabolic agent when given intermittently, stimulating osteoblast activity more than osteoclast activity and promoting new bone formation. In clinical use, teriparatide increases vertebral and hip bone mineral density and reduces the risk of vertebral and nonvertebral fractures in adults with osteoporosis.

Indications include osteoporosis in adults at high fracture risk, including postmenopausal women, men with osteoporosis, and glucocorticoid-induced osteoporosis. It is typically prescribed for those who have failed or cannot tolerate other osteoporosis therapies, or who need rapid fracture risk reduction. Dosing is via subcutaneous injection once daily, traditionally 20 micrograms, for up to 24 months of therapy over a patient’s lifetime, with a recommended limit on cumulative duration of use.

Contraindications and precautions include hypercalcemia; known hypersensitivity to teriparatide or any excipients; history of bone cancer or skeletal metastases; prior radiation therapy involving the skeleton; Paget disease of bone; unexplained elevations of alkaline phosphatase; pregnancy and lactation. Caution is advised in patients with elevated calcium levels or renal impairment. Teriparatide is not approved for use in children.

Common adverse effects include nausea, leg cramps, dizziness, and injection-site reactions; orthostatic hypotension can occur after the first dose. There is a theoretical risk of osteosarcoma observed in animal studies, leading to a lifetime duration limit and use with caution in individuals with conditions that may predispose to bone cancer.

Brand names include Forteo, produced by Eli Lilly. Teriparatide is one component of a broader osteoporosis treatment landscape and is often followed by antiresorptive therapy to maintain gains in bone density.