What is the most appropriate additional antiresorptive therapy for a 33-year-old woman with steroid-induced osteoporosis, adrenal insufficiency, and a history of avascular necrosis of femoral heads?

Management of Steroid-Induced Osteoporosis in a Young Woman with Avascular Necrosis

Risedronate is the most appropriate additional antiresorptive therapy for this 33-year-old woman with steroid-induced osteoporosis, adrenal insufficiency, and history of avascular necrosis of femoral heads. 1

Patient Risk Assessment

This patient presents with several critical risk factors:

• 33-year-old woman (premenopausal)
• Severe reactive airway disease requiring glucocorticoid therapy
• Adrenal insufficiency from exogenous glucocorticoid therapy
• Bilateral hip replacement due to avascular necrosis of femoral heads
• Already started on calcium (1,500 mg) and vitamin D (800 IU) supplementation

Based on the 2022 American College of Rheumatology (ACR) guidelines for glucocorticoid-induced osteoporosis (GIOP), this patient falls into the "very high fracture risk" category for adults <40 years due to:

• Prior fractures/joint damage (avascular necrosis requiring bilateral hip replacement)
• Likely history of high-dose glucocorticoid use (≥30 mg/day) or cumulative dose ≥5 g/year 1

Treatment Recommendation Algorithm

1. First-line therapy: Oral bisphosphonate (risedronate)

   • For adults <40 years at very high risk of fracture, the ACR guidelines conditionally recommend oral bisphosphonates as first-line therapy 1
   • Risedronate is specifically preferred in this case due to its:
     • Established efficacy in GIOP
     • Shorter skeletal half-life compared to alendronate (important for a young woman who may become pregnant in the future) 1

2. Alternative options (if oral bisphosphonates are contraindicated):

   • IV bisphosphonates (second choice)
   • PTH/PTHrP analogs (teriparatide/abaloparatide) (third choice)
   • Denosumab (fourth choice) 1

3. Not recommended in this case:

   • Raloxifene: Conditionally recommended against in adults <40 years due to risk of venous thromboembolism (VTE) and fatal stroke 1
   • Calcitonin: Weaker efficacy data compared to other options 1
   • Sodium fluoride: Not recommended in current guidelines for GIOP
   • Oral contraceptives: Not specifically recommended for GIOP management

Rationale for Choosing Risedronate

1. Efficacy in GIOP:

   • Bisphosphonates are strongly recommended for GIOP management with high-quality evidence supporting fracture reduction 1
   • Risedronate specifically has demonstrated rapid fracture risk reduction (within 6 months) 2

2. Safety considerations:

   • Risedronate has a shorter skeletal half-life than alendronate, making it preferred in younger women who may become pregnant in the future 1
   • This is particularly important given the patient's young age (33 years)

3. Contraindications for other options:

   • Raloxifene is conditionally recommended against in adults <40 years due to risk of VTE 1
   • Calcitonin has weaker efficacy data compared to bisphosphonates 1
   • Oral contraceptives are not specifically recommended for GIOP management

Monitoring and Follow-up

• BMD with vertebral fracture assessment (VFA) or spinal x-ray every 1-2 years during treatment 1
• Continue calcium (1,500 mg) and vitamin D (800 IU) supplementation
• Assess adherence to therapy at each follow-up visit
• Monitor for potential side effects of bisphosphonates (gastrointestinal symptoms, musculoskeletal pain)

Important Considerations

• Avascular necrosis history: This patient's history of avascular necrosis of femoral heads from steroid therapy indicates severe adverse effects from glucocorticoids, highlighting the urgent need for effective bone protection 3, 4

• Adrenal insufficiency: The patient's adrenal insufficiency indicates long-term, high-dose steroid exposure, further supporting the need for aggressive bone protection 1

• Premenopausal status: While GIOP guidelines apply regardless of menopausal status, special consideration is needed for potential future pregnancy. Risedronate's shorter skeletal half-life makes it preferable to alendronate in this context 1

By implementing risedronate therapy alongside the already prescribed calcium and vitamin D supplementation, this patient will receive appropriate protection against further bone loss and fractures related to her glucocorticoid therapy and existing bone damage.