Calcitonin (Miacalcin/Fortical) - Salmon Calcitonin for Bone Disease — Bone & Mineral

FDA-approved synthetic salmon calcitonin for postmenopausal osteoporosis, Paget's disease, and hypercalcemia.

Overview

Calcitonin (salmon) is a synthetic polypeptide hormone FDA-approved for postmenopausal osteoporosis (≥5 years postmenopause), Paget's disease of bone, and hypercalcemia. It inhibits osteoclast-mediated bone resorption and promotes renal calcium excretion. PROOF study (5-year RCT, n=1,255) showed 33% reduction in vertebral fractures with intranasal 200 IU daily, though no effect on hip/non-vertebral fractures. In Paget's disease, chronic treatment reduced alkaline phosphatase ~50% with relief of bone pain and neurological symptoms. Available as intranasal spray (Miacalcin, Fortical) or injection. NOTE: FDA added boxed warning in 2015 due to slightly higher malignancy rates in meta-analysis (4.1% vs 2.9% placebo), primarily basal cell carcinoma. Generally considered second-line therapy after bisphosphonates/newer agents due to limited fracture data and cancer signal.

Indications

  • Postmenopausal osteoporosis (≥5 years postmenopause) - second-line
  • Paget's disease of bone
  • Hypercalcemia (emergency management)
  • Acute pain from osteoporotic vertebral fractures (analgesic effect)

Mechanism of Action

Osteoporosis: excessive osteoclast activity. Paget's disease: abnormal bone turnover. Hypercalcemia: elevated serum calcium

Dosing

CompoundDoseFrequencyNotes
Salmon calcitonin nasal spray 200 IU200 IU (1 spray) in one nostrilOnce dailyAlternate nostrils daily; add calcium 1000 mg + vitamin D 400-800 IU daily
Salmon calcitonin nasal spray 200-400 IU200-400 IUOnce or twice weeklyAdd calcium 500 mg TID + thiazide diuretic for enhanced effect
Salmon calcitonin injection 100 IU/mL100 IU SC or IMDaily or 3x/weekFor severe Paget's; may reduce to maintenance dosing once controlled
Salmon calcitonin injection 100 IU/mL4-8 IU/kg SC or IMEvery 12 hoursEmergency management; combine with IV fluids and bisphosphonates

Evidence Grade

GRADE B

Safety & Contraindications

  • ⚠️ PRESCRIPTION MEDICATION - Physician supervision required
  • ⚠️ FDA BOXED WARNING (2015): Meta-analysis showed slightly higher cancer rates (4.1% vs 2.9% placebo), particularly basal cell carcinoma - risk/benefit assessment required for prolonged use
  • Generally second-line therapy after bisphosphonates, denosumab, or anabolic agents
  • Antibody formation: ~20% develop neutralizing antibodies (especially with long-term use); may switch to human calcitonin if resistance develops
  • Nasal irritation: Common with intranasal spray (rhinitis, epistaxis, nasal ulceration)
  • Flushing: 2-5% with injection form (transient, dose-related)
  • Hypocalcemia: Rare but monitor calcium in patients with low baseline calcium
  • Hypersensitivity reactions: Rare anaphylaxis; skin testing recommended before first injection dose
  • Refrigeration required for injection; nasal spray stable at room temp after opening