Teriparatide (Forteo) - Recombinant PTH(1-34) for Osteoporosis — Bone & Mineral

FDA-approved recombinant parathyroid hormone (PTH 1-34) for severe osteoporosis and fracture prevention - first anabolic bone agent.

Overview

Teriparatide (Forteo) is recombinant human parathyroid hormone consisting of the first 34 amino acids of PTH. FDA-approved November 2002 as the first anabolic agent for osteoporosis. Landmark Phase 3 trial (n=1,637) showed 65% reduction in vertebral fractures, 53% reduction in non-vertebral fractures, +9% lumbar spine BMD, and +3% femoral neck BMD. Unlike antiresorptive agents, teriparatide stimulates new bone formation via intermittent PTH exposure. Maximum treatment duration: 24 months (2-year lifetime limit). Indicated for postmenopausal women, men, and glucocorticoid-induced osteoporosis at high fracture risk. Requires sequential therapy with antiresorptive (bisphosphonate/denosumab) to maintain gains.

Indications

  • Severe osteoporosis in postmenopausal women at high fracture risk
  • Men with osteoporosis at high fracture risk
  • Glucocorticoid-induced osteoporosis (men & women)
  • Prior osteoporotic fractures or very low BMD (T-score ≤-2.5)
  • Failed or intolerant to antiresorptive therapy

Mechanism of Action

Low bone mass, prior fractures, or failed antiresorptive therapy

Dosing

CompoundDoseFrequencyNotes
Teriparatide 20 mcg pre-filled pen20 mcg SC dailyOnce dailyInject into thigh or abdomen; rotate sites; maximum 24 months lifetime use
Teriparatide 20 mcg pre-filled pen20 mcg SC dailyOnce dailySuperior to alendronate; approved 2009 for GC-induced osteoporosis

Evidence Grade

GRADE A

Safety & Contraindications

  • ⚠️ PRESCRIPTION MEDICATION - Physician supervision required
  • LIFETIME LIMIT: 24 months maximum cumulative use (2-year limit)
  • Former FDA boxed warning for osteosarcoma (based on rat studies) was REMOVED after 15+ years of human data showed no increased risk
  • Transient hypercalcemia: Self-limiting mild elevations common; monitor calcium if symptomatic
  • Orthostatic hypotension: May cause transient dizziness; inject while sitting
  • CONTRAINDICATIONS: Paget's disease, unexplained elevated alkaline phosphatase, skeletal malignancies, prior radiation to skeleton, hyperparathyroidism, severe renal impairment
  • NOT for children/adolescents (open growth plates)
  • Common side effects: Nausea (14%), gastritis, leg cramps, dizziness
  • Must refrigerate pen; expensive (~$1,000/month brand, lower for generics)