What is the recommended dosing regimen for Forteo (teriparatide) in the treatment of osteoporosis?

Forteo (Teriparatide) Dosing for Osteoporosis Treatment

The recommended dosing regimen for Forteo (teriparatide) is 20 mcg administered subcutaneously once daily into the thigh or abdominal region for a maximum treatment duration of 2 years during a patient's lifetime. 1

Administration Guidelines

• Teriparatide should be administered as a subcutaneous injection only (not approved for intravenous or intramuscular use)
• Initial administration should occur under circumstances where the patient can sit or lie down if orthostatic hypotension occurs
• The solution should be clear and colorless; do not use if solid particles appear or if solution is cloudy or colored
• Patients/caregivers should receive proper training on the delivery device from a qualified healthcare professional

Treatment Duration

• Maximum treatment duration is 2 years during a patient's lifetime 1
• Extended use beyond 2 years should only be considered if a patient remains at or has returned to having a high risk for fracture 1
• The limitation on treatment duration is due to the potential risk of osteosarcoma observed in animal studies 1, 2

Indications for Teriparatide

Teriparatide is indicated for:

1. Treatment of postmenopausal women with osteoporosis at high risk for fracture
2. Increasing bone mass in men with primary or hypogonadal osteoporosis at high risk for fracture
3. Treatment of men and women with osteoporosis associated with sustained systemic glucocorticoid therapy (≥5 mg prednisone equivalent daily) 1

Patient Selection

Teriparatide is typically reserved for:

• Patients with severe osteoporosis or who have had fractures 3
• Patients who cannot tolerate other osteoporosis treatments 3
• Adults ≥40 years at very high fracture risk, especially those on high-dose glucocorticoids (≥30 mg daily for ≥30 days or cumulative dose ≥5g over 1 year) 3, 4

Supplementation Requirements

• Patients should take supplemental calcium and vitamin D if daily dietary intake is inadequate 1
• Adequate calcium (1,000-1,200 mg/day) and vitamin D (600-800 IU/day) supplementation is recommended 4

Contraindications

Teriparatide is contraindicated in patients with:

• Hypersensitivity to teriparatide or its excipients 1
• Open epiphyses (pediatric and young adult patients) 1
• Metabolic bone diseases other than osteoporosis 1
• Bone metastases or history of skeletal malignancies 1
• Prior radiation therapy involving the skeleton 1
• Hereditary disorders predisposing to osteosarcoma 1

Monitoring

• Initial administration should be supervised to monitor for orthostatic hypotension 1
• Serum calcium levels should be monitored, as teriparatide may cause hypercalcemia 1
• Patients with active or recent urolithiasis require careful consideration due to potential exacerbation 1

Post-Treatment Considerations

• After completing teriparatide therapy, patients should transition to an antiresorptive agent to maintain bone gains and prevent rebound bone loss 4
• Long-term studies show that teriparatide can reduce fracture prevalence to levels similar to the general population even at 10-year follow-up 5

Common Side Effects

• Dizziness and leg cramps are common side effects 3
• Hypercalcemia (usually mild and transient) may occur, typically 4-6 hours after injection 6
• Urinary calcium excretion may increase by approximately 30 mg/day 6

Teriparatide represents a unique anabolic (bone-forming) approach to osteoporosis treatment, distinct from antiresorptive agents like bisphosphonates, and should be considered for patients with severe osteoporosis who are at high risk for fracture.