Forteo

• Osteoporosis in Postmenopausal Women: To increase bone mass and reduce risk of fractures in patients at high risk of fracture.
• Osteoporosis in Men: For treatment of primary or hypogonadal osteoporosis with high fracture risk.
• Glucocorticoid-Induced Osteoporosis: For patients receiving long-term glucocorticoids who are at increased risk of fracture.
• Other Clinically Accepted Uses: Occasionally off-label for delayed fracture healing or severe osteoporosis not responsive to other therapies.

• Route: Subcutaneous injection.
• Adult Dose: 20 mcg once daily into the thigh or abdomen.
• Duration: Recommended treatment duration is up to 24 months due to risk profile.
• Pediatrics: Not established.
• Elderly: No dose adjustment needed but monitor closely.
• Renal/Hepatic Impairment: Use with caution; limited data, no formal dose adjustments.
• Administration Notes:
• Inject once daily at any time of day, with or without food.
• Rotate injection sites.
• Do not exceed 24 months cumulative lifetime use.

Teriparatide is a recombinant form of human parathyroid hormone (PTH 1-34) that binds to PTH-1 receptors on osteoblasts, stimulating new bone formation. Unlike continuous PTH exposure which leads to bone resorption, intermittent administration promotes osteoblastic activity, increasing bone remodeling and net bone formation. This anabolic effect improves bone mineral density and strength, reducing fracture risk.

• Absorption: Rapid after subcutaneous injection with peak plasma concentrations in ~30 minutes.
• Bioavailability: Approximately 95%.
• Distribution: Widely distributed, especially in bone tissue.
• Metabolism: Degraded enzymatically, primarily by liver and kidneys.
• Half-Life: ~1 hour.
• Excretion: Primarily renal.

• Pregnancy: FDA Category C — Animal studies show fetal harm at high doses; no adequate human studies. Avoid use during pregnancy.
• Lactation: Unknown if excreted in human milk; caution advised. Avoid use unless benefits outweigh risks.

• Primary Class: Bone anabolic agent
• Subclass: Recombinant parathyroid hormone analog

• Hypersensitivity to teriparatide or excipients
• Patients with bone malignancies or history of skeletal radiation
• Hypercalcemia
• Patients at increased baseline risk of osteosarcoma (e.g., Paget’s disease)
• Pregnant or breastfeeding women

• Risk of osteosarcoma observed in rat studies; clinical relevance uncertain but limits treatment duration to 24 months.
• Monitor serum calcium; transient hypercalcemia may occur.
• Use cautiously in patients with increased risk of bone tumors.
• Not recommended for patients with unexplained elevated alkaline phosphatase.
• Monitor for symptoms of hypercalcemia (nausea, weakness).
• Caution in renal impairment; risk of hypercalcemia may be increased.

Common:

• Injection site reactions (pain, redness, swelling)
• Nausea
• Headache
• Dizziness
• Leg cramps

Serious (Rare):

• Hypercalcemia
• Orthostatic hypotension
• Urolithiasis (kidney stones)
• Osteosarcoma (risk theoretical)

• Caution with digoxin due to risk of hypercalcemia enhancing digoxin toxicity.
• Use with caution alongside other hypercalcemic agents (e.g., thiazides).
• No significant CYP450 involvement.

• FDA and EMA restrict lifetime use to 24 months due to safety concerns.
• Guidelines endorse teriparatide for severe osteoporosis and glucocorticoid-induced osteoporosis when other therapies are insufficient.
• Recent recommendations emphasize follow-up antiresorptive therapy post-teriparatide to maintain gains.

• Store refrigerated at 2°C to 8°C (36°F to 46°F).
• Protect from light; keep in original carton.
• Do not freeze.
• Can be kept at room temperature (up to 25°C) for up to 28 days during use.
• Discard unused solution after 28 days of first use.