Contraindications to Forteo (Teriparatide)
Forteo is absolutely contraindicated in patients with hypersensitivity to teriparatide or any of its excipients, including those with prior angioedema or anaphylaxis. 1
Absolute Contraindication
- Hypersensitivity reactions: Patients with known hypersensitivity to teriparatide or any excipients must not receive this medication, as serious reactions including angioedema and anaphylaxis have been documented. 1
Conditions Where Forteo Should Be Avoided (Increased Baseline Osteosarcoma Risk)
The FDA drug label explicitly states that teriparatide should be avoided in patients with increased baseline risk of osteosarcoma, which includes: 1
Open epiphyses: Pediatric and young adult patients with open growth plates should not receive teriparatide (the drug is not approved for pediatric use). 1
Paget's disease of bone: Patients with this metabolic bone disease have increased osteosarcoma risk and should avoid teriparatide. 2, 1
Prior skeletal radiation therapy: External beam or implant radiation involving the skeleton is a contraindication due to increased osteosarcoma risk. 2, 1, 3 While some case series suggest cautious use in select severe cases where benefits may outweigh risks, this remains controversial and requires careful risk-benefit assessment. 4
Bone metastases or history of skeletal malignancies: Patients with bone metastases or prior skeletal malignancies should not receive teriparatide. 2, 1 The drug increases bone turnover, which may theoretically promote propagation of microscopic bone metastases through liberation of bone-derived growth factors. 2
Hereditary disorders predisposing to osteosarcoma: Any genetic condition that increases osteosarcoma risk is a contraindication. 1
Additional Clinical Situations Requiring Avoidance
Pre-existing hypercalcemia: Teriparatide can cause or exacerbate hypercalcemia and should be avoided in patients with underlying hypercalcemic disorders such as primary hyperparathyroidism. 1 This is particularly important as the drug is a parathyroid hormone analog. 5
Active urolithiasis: While not an absolute contraindication, the FDA label recommends careful consideration of risks versus benefits in patients with active or recent kidney stones, as teriparatide may exacerbate this condition through effects on calcium metabolism. 1
Important Clinical Context
The osteosarcoma concern stems from rat studies where nearly 45% of rats treated at the highest doses developed osteosarcoma, leading to an FDA black box warning. 1, 3 However, observational studies in over 430,000 human patients have not demonstrated an increased osteosarcoma risk compared to the general population. 2, 3 Despite this reassuring human data, the contraindications remain in place for patients with baseline increased osteosarcoma risk.
Duration limitation: The FDA recommends that use beyond 2 years during a patient's lifetime should only be considered if the patient remains at or has returned to high fracture risk. 1
Special Populations Requiring Caution
Malignancies prone to bone metastases: Even with remote cancer history, teriparatide is best avoided in patients with cancers that commonly metastasize to bone (breast, prostate, lung, kidney, thyroid). 2 In exceptional cases of severe osteoporosis with fractures despite bisphosphonate therapy and remote cancer history, cautious consideration may be warranted. 2
Patients at risk for calciphylaxis: Those with underlying autoimmune disease, kidney failure, or concomitant warfarin/systemic corticosteroid use have increased risk of calciphylaxis and should be monitored closely or avoid the drug. 1