PH7.2 | PH7.2 | Osteoporosis Pharmacotherapy — SDL Guide — Summary & Reflection

KEY TAKEAWAYS

Osteoporosis Pharmacotherapy — Key Takeaways:

• Anti-resorptive agents: bisphosphonates (inhibit farnesyl pyrophosphate synthase in osteoclasts), denosumab (RANK-L antibody), raloxifene (SERM — vertebral benefit only, no hip), calcitonin (modest efficacy, analgesic niche).
• Anabolic agents: teriparatide [PTH(1-34)] — intermittent pulsatile → osteoblast activation; maximum 24 months lifetime (animal osteosarcoma data); romosozumab (anti-sclerostin) — dual anabolic+anti-resorptive, 12 months only, contraindicated within 12 months of MI/stroke.
• Renal thresholds: bisphosphonates — avoid eGFR <30–35 (oral); IV zoledronate contraindicated <35. Denosumab — no renal adjustment (preferred in CKD; watch hypocalcaemia).
• Denosumab discontinuation: transition to bisphosphonate — abrupt stop causes RANK-L rebound and multiple vertebral fractures.
• After teriparatide: MUST start anti-resorptive to preserve gains.
• Female first-line: alendronate/risedronate (or zoledronate IV); severe disease → teriparatide then anti-resorptive.
• Male: same bisphosphonates; denosumab for ADT-associated bone loss; treat secondary causes.
• Calcium + Vitamin D: adjuncts, not primary therapy.

REFLECT

Consider a patient who has been on bisphosphonate therapy for 7 years and now presents with thigh pain. The X-ray shows a subtle horizontal fracture line in the lateral femoral cortex with 'beaking.' What would you think of? What drug-related complication is this? What do you do next? Reflect on the relationship between long-term drug benefit and rare late-onset adverse effects — and how monitoring for atypical femoral fracture is part of the bisphosphonate drug holiday conversation. Write three points: (1) the diagnosis, (2) the pharmacological mechanism, (3) your management including implications for the patient's future osteoporosis treatment.