Teriparatide

What is Teriparatide?

Teriparatide is a recombinant parathyroid hormone (PTH 1‑34) analog with anabolic (bone‑building) effects. It stimulates new bone formation, increases bone mineral density, and strengthens skeletal structure, reducing fracture risk in people with osteoporosis.

Approved Uses

Teriparatide is FDA-approved for:

1. Postmenopausal women with osteoporosis are at high risk for fractures, or who can’t tolerate other therapies.

2. Men with primary or hypogonadal osteoporosis are at high fracture risk.

3. Patients on chronic glucocorticoid therapy (e.g., prednisone ≥5 mg daily) who are osteoporosis patients at high fracture risk

How It Works

• Teriparatide is a synthetic fragment of human PTH (first 34 amino acids).

• Unlike continuous PTH exposure, intermittent daily dosing preferentially stimulates osteoblast activity over osteoclasts, leading to net bone gain.

• It acts on PTH1 receptors, boosting bone formation on both trabecular and cortical surfaces.

Dosage & Administration

• Route: Subcutaneous injection, usually with a daily pre-filled pen delivering 20 µg

• Injection site: thigh or abdomen; change sites regularly.

• Treatment duration: Up to 2 years total in a patient’s lifetime; use beyond requires high fracture-risk justification.

• Store in refrigerated conditions and discard the pen after 28 days of first use

Safety & Precautions

• Black-box warning: Risk of osteosarcoma observed in rats; human cases are extremely rare (≈1 per 100,000), and use is contraindicated in conditions predisposing to bone cancer.

• Avoid in pediatric/young adult patients with open epiphyses, metabolic bone diseases, Paget’s disease, bone metastases, or prior bone radiation.

• Common side effects: nausea, headache, dizziness, limb pain, hypercalcemia; an acute drop in blood pressure can occur soon after injection.

• Monitor serum calcium; advise against use if history of hypercalcemia, kidney stones, or significant renal impairment.

• Watch for signs of hypersensitivity reactions like hives or swelling.
  

Clinical Benefits

• In a major trial, daily 20 µg reduced vertebral fracture risk by 65% and non-vertebral fractures by 53%; lumbar spine BMD increased by ~9%, femoral neck by ~3% within 21 months.
• Teriparatide significantly reduces hip fracture risk compared to placebo