What is the recommended dose of calcitonin (Calcitonin) for treating osteoporosis and Paget's disease?

Calcitonin Dosage for Osteoporosis and Paget's Disease

For osteoporosis, the recommended dose of calcitonin is 200 IU daily administered as a nasal spray, while for Paget's disease, the dose is 100 IU administered subcutaneously or intramuscularly every other day. These dosages are supported by clinical guidelines and FDA labeling.

Calcitonin for Osteoporosis

Dosage and Administration

• Nasal spray formulation: 200 IU (one spray) daily, alternating nostrils daily 1
• Administration should continue for at least 4 weeks for acute pain management in osteoporotic vertebral fractures 2
• Patients should receive adequate calcium (at least 1000 mg elemental calcium per day) and vitamin D (at least 400 IU per day) supplementation 1

Clinical Considerations

• Calcitonin should be reserved as a second-line therapy for osteoporosis when other treatments cannot be used 3
• It has weaker efficacy data compared to bisphosphonates, raloxifene, denosumab, and teriparatide 3
• Most appropriate for women with less serious osteoporosis who cannot tolerate other treatments 3
• The PROOF study demonstrated that nasal calcitonin at 200 IU/day reduced vertebral fracture risk by 33%, though effects on non-vertebral fractures were not significant 4

Calcitonin for Paget's Disease

Dosage and Administration

• Injectable formulation: 100 IU subcutaneously or intramuscularly every other day 3, 1
• For severe bone pain in Paget's disease, this dosage has shown effectiveness in reducing symptoms

Monitoring and Duration

• For both indications, bone mineral density (BMD) should be measured yearly while on treatment 3
• If deterioration in BMD (>4% per year) occurs over two successive years, consider changing treatment 3
• If no deterioration, treatment should continue for at least three years, or as long as osteoporosis persists 3

Important Precautions

Contraindications

• Hypersensitivity to calcitonin-salmon or any excipients 1
• History of serious allergic reactions including anaphylaxis, bronchospasm, or swelling of tongue/throat 1

Side Effects

• Nasal formulation: mild nasal irritation (32% incidence) 5
• Injectable formulation: nausea, vomiting, flushing (64-77% incidence) 5
• Long-term administration appears safe without serious long-term side effects 5

Antibody Development

• Antibodies against salmon calcitonin develop in 40-70% of patients treated for more than 4 months 6
• Secondary resistance occurs in 25-45% of patients after 6+ months of treatment 6

Clinical Decision Algorithm

1. First determine if calcitonin is appropriate:

   • Use only after first-line therapies (bisphosphonates) are contraindicated or not tolerated
   • Verify patient has no history of hypersensitivity to calcitonin

2. For osteoporosis:

   • Prescribe 200 IU nasal spray daily
   • Ensure patient is >5 years postmenopausal if female
   • Add calcium (1000-1500 mg/day) and vitamin D (400-800 IU/day)

3. For Paget's disease:

   • Prescribe 100 IU subcutaneously or intramuscularly every other day
   • Monitor alkaline phosphatase levels to assess response

4. For acute vertebral fracture pain:

   • Prescribe 200 IU nasal spray daily for 4 weeks
   • Transition to more effective long-term therapy afterward

5. Monitor treatment effectiveness:

   • Measure BMD yearly
   • Assess for development of antibodies if effectiveness wanes

Remember that calcitonin is generally not a first-line therapy for either condition but can be valuable in specific clinical scenarios, particularly for short-term pain management in acute vertebral fractures.