Is Forteo (teriparatide) safe for osteoporosis treatment in a patient with frontotemporal dementia, hypothyroidism, and a history of breast cancer?

Teriparatide (Forteo) is Contraindicated in Patients with History of Breast Cancer

Teriparatide (Forteo) should not be used for osteoporosis treatment in patients with frontotemporal dementia, hypothyroidism, and a history of breast cancer due to the contraindication in patients with a history of skeletal malignancies or cancers prone to metastasize to bone. 1, 2

Rationale for Contraindication

Teriparatide carries significant risks in patients with breast cancer history:

• The FDA label explicitly lists "bone metastases or a history of skeletal malignancies" as contraindications 2
• NCCN guidelines recommend avoiding teriparatide in patients with a history of malignancy prone to metastasize to bone, which includes breast cancer 3
• The mechanism of action raises theoretical concerns about promoting microscopic bone metastases through:
  • Liberation of bone-derived growth factors and cytokines
  • Potential direct anabolic effects on tumor cells 1

Alternative Treatment Options for This Patient

First-Line Recommendation

• Denosumab (Prolia) 60mg subcutaneously every 6 months is the preferred first-line option 3
  • Not affected by the patient's hypothyroidism
  • Highly effective at reducing vertebral, non-vertebral, and hip fractures
  • RANK-L inhibitor that blocks osteoclast differentiation and function

Alternative Options

• Bisphosphonates (oral or IV) are considered the best choice for preventing bone loss or treating established osteoporosis in women with a history of breast cancer 1
  • Zoledronic acid (IV) may be appropriate with dose adjustment if renal function is impaired
  • Oral bisphosphonates (alendronate, risedronate) are also effective options

Special Considerations for This Patient

Frontotemporal Dementia

• Ensure medication administration compliance
• Consider once-yearly zoledronic acid or twice-yearly denosumab for simplified regimen
• Evaluate cognitive ability to manage self-injections if considering denosumab

Hypothyroidism

• Ensure hypothyroidism is well-controlled before initiating osteoporosis treatment
• Poorly controlled hypothyroidism can contribute to bone loss
• No specific contraindications for denosumab or bisphosphonates with hypothyroidism

Monitoring Recommendations

1. Baseline dental examination before starting therapy to assess risk of osteonecrosis of the jaw
2. Calcium and vitamin D levels before and during treatment
3. Renal function monitoring if using bisphosphonates
4. BMD testing after 1-2 years to assess treatment response

Common Pitfalls to Avoid

1. Do not use teriparatide even in cases of severe osteoporosis with fractures in this patient population - the theoretical risk of promoting bone metastases outweighs potential benefits 1
2. Avoid inadequate calcium and vitamin D supplementation (recommend 1,200 mg calcium and 800-1,000 IU vitamin D daily) 3
3. Do not use raloxifene with aromatase inhibitors if the patient is on breast cancer treatment 1
4. Ensure proper monitoring for hypocalcemia with denosumab, particularly in patients with renal impairment

While teriparatide is highly effective for severe osteoporosis, the presence of breast cancer history creates an absolute contraindication that cannot be overlooked, regardless of the severity of osteoporosis or presence of other conditions like frontotemporal dementia or hypothyroidism.