Teriparatide Dosing Regimen for Osteoporosis
The standard dose is 20 mcg administered subcutaneously once daily into the thigh or abdominal region, with treatment duration limited to 2 years during a patient's lifetime unless the patient remains at or returns to very high fracture risk. 1
Standard Dosing Protocol
- Administer 20 mcg subcutaneously once daily as the therapeutic dose 2, 1
- Inject into the thigh or abdominal region 1
- Initial doses should be given under circumstances where the patient can sit or lie down due to risk of transient orthostatic hypotension 1
Treatment Duration
- Maximum treatment duration is 2 years during a patient's lifetime 2, 1
- This limitation stems from historical osteosarcoma concerns in animal studies, though a study of 200,000 patients showed no significant difference in osteosarcoma incidence compared to the general population 3, 2
- Treatment beyond 2 years should only be considered if the patient remains at or has returned to very high fracture risk 1
Required Supplementation
- Calcium: 1,000-1,200 mg daily 3, 2, 1
- Vitamin D: 600-800 IU daily (target serum level ≥20 ng/mL) 3, 2, 1
- Supplementation should be optimized based on individual laboratory values and patient needs 2, 1
Patient Selection Criteria
Teriparatide is reserved for specific high-risk populations, not as first-line therapy:
- Severe osteoporosis with documented fractures 3
- Very high fracture risk (T-score ≤ -3.5, multiple prevalent fractures, or fractures occurring despite therapy) 3
- Patients who have failed or cannot tolerate bisphosphonates 3, 1, 4
- Glucocorticoid-induced osteoporosis at very high fracture risk 3, 2, 1
The American College of Rheumatology conditionally recommends teriparatide over anti-resorptives only in patients at very high fracture risk 3, making bisphosphonates the first-line therapy for most patients.
Critical Contraindications
Absolute contraindications include:
- Open epiphyses 1
- Paget's disease of bone 1
- Bone metastases or history of skeletal malignancies 3, 1
- Prior external beam or implant radiation therapy involving the skeleton 3, 1
- Hypersensitivity to teriparatide or its excipients 1
Use with extreme caution or avoid in:
- Patients with cancer or history of malignancy prone to metastasize to bone 3, 2, 5
- Underlying hypercalcemic disorders 1
- Active or recent urolithiasis (risk of exacerbation) 1
- Pre-existing cardiac arrhythmias 2, 5
Sequential Therapy Considerations
- Following teriparatide completion, transition to antiresorptive therapy (bisphosphonate or denosumab) to preserve bone mass gains 6
- Prior bisphosphonate treatment may diminish the bone anabolic potential of teriparatide 6
- Teriparatide is best given as monotherapy, not in combination with bisphosphonates 6
- In men with osteoporosis, teriparatide followed by risedronate showed superiority over risedronate alone, supporting sequential therapy 7
Clinical Efficacy Timeline
- Fracture risk reduction becomes evident after 8-12 months of treatment 6
- Vertebral fracture risk reduced by 65% and nonvertebral fragility fractures by 53% in postmenopausal women 8
- Spine BMD increases by approximately 10% and hip BMD by 3% at study endpoint 8
- In men with osteoporosis, teriparatide significantly improved lumbar spine BMD (MD 8.19%) and femoral neck BMD (MD 1.33%) 7
Common Pitfalls to Avoid
- Do not use as first-line therapy - generic bisphosphonates should be prescribed first due to significantly lower cost 3
- Do not extend beyond 2 years without documented persistent very high fracture risk 1
- Do not use in pediatric patients due to increased baseline risk of osteosarcoma 1
- Do not combine with bisphosphonates during active treatment, as this diminishes anabolic effects 6
- Monitor for transient hypercalcemia, especially in patients on digoxin (risk of digitalis toxicity) 1