Teriparatide
Teriparatide (Forteo) is recombinant human parathyroid hormone (1-34), FDA-approved for osteoporosis treatment. It's unique among osteoporosis drugs in that it stimulates new bone formation.
Mechanism of Action
Intermittent PTH exposure paradoxically stimulates osteoblasts more than osteoclasts, resulting in net bone formation. Continuous exposure would cause bone loss, but pulsatile dosing builds bone.
Typical Dosage (Research)
20mcg subcutaneously once daily. Maximum treatment duration of 2 years due to theoretical osteosarcoma risk from rat studies.
Subcutaneous injection in thigh or abdomen once daily. Delivered via multi-dose pen. Should sit or lie down after injection due to orthostatic hypotension risk.
Side Effects & Risks
Orthostatic hypotension, leg cramps, nausea, dizziness, headache, and injection site reactions. Transient hypercalcemia possible.
Boxed warning for osteosarcoma risk (seen in rat studies at high doses). Contraindicated in Paget's disease, unexplained elevated ALP, prior bone radiation, or bone metastases.
Who Uses Teriparatide
Post-menopausal women with severe osteoporosis, men with osteoporosis, those with fractures despite other treatments.