What are the indications for calcitonin (Calcitonin) injections?

Indications for Calcitonin Injections

Calcitonin injections are primarily indicated for the treatment of symptomatic Paget's disease of bone when alternative treatments are not suitable, treatment of hypercalcemia, and treatment of postmenopausal osteoporosis when alternative treatments are not suitable. 1

FDA-Approved Indications

• Treatment of symptomatic Paget's disease of bone when alternative treatments are not suitable 1
• Treatment of hypercalcemia 1
• Treatment of postmenopausal osteoporosis when alternative treatments are not suitable (though fracture reduction efficacy has not been demonstrated) 1

Clinical Applications in Bone Disorders

• Paget's disease: Calcitonin has documented efficacy in treating Paget's disease, with effects of a single injection potentially lasting for months 2
• Malignant osteolysis: Calcitonin has shown effectiveness in treating bone destruction associated with malignancy 2
• High-turnover osteoporosis: This naturally occurring hormone has been studied extensively for this indication 2
• Conventional osteoporosis: Calcitonin has demonstrated ability to protect bone mass in conventional osteoporosis 2

Pain Management Applications

• Acute vertebral compression fractures: For patients with acute osteoporotic spinal compression fractures, calcitonin (100 IU subcutaneously or intramuscularly every other day) can provide significant pain relief 3, 4
• Chronic bone pain: Calcitonin has demonstrated efficacy in treating chronic back pain following vertebral fractures in spinal osteoporosis 4, 5

Dosing Recommendations

• For Paget's disease: 100 International Units daily with adequate calcium and vitamin D intake 1
• For hypercalcemia: Starting dose of 4 International Units/kg body weight every 12 hours, with potential increase to 8 International Units/kg every 12 hours if no improvement in 1-2 days, and further increase to 8 International Units/kg every 6 hours if needed 1
• For postmenopausal osteoporosis: 100 International Units daily with adequate calcium and vitamin D intake 1

Important Limitations and Considerations

• Calcitonin therapy should be periodically reevaluated due to possible association between malignancy and calcitonin-salmon use 1
• Injectable forms have been largely replaced by nasal spray formulations due to improved patient acceptance and fewer side effects 2
• Calcitonin acts primarily by inhibiting osteoclast action, thereby reducing bone resorption 2
• Some in vitro data suggests calcitonin may also stimulate osteoblast function 2

Contraindications and Side Effects

• Contraindicated in patients with hypersensitivity to calcitonin-salmon or any of the excipients 1
• Most common adverse reactions include nausea with or without vomiting (10%), injection site inflammation (10%), and flushing of the face or hands (2% to 5%) 1
• Serious hypersensitivity reactions, including reports of fatal anaphylaxis, have been reported 1
• Hypocalcemia can occur, so adequate intake of calcium and vitamin D should be ensured 1

Clinical Pearls

• Circulating antibodies to calcitonin-salmon may develop over time, potentially causing loss of response to treatment 1
• When using calcitonin with lithium, monitor for reduced plasma lithium concentrations due to increased urinary clearance of lithium 1
• For patients with established osteoporosis, combination therapy with calcitriol, calcium, and calcitonin may improve bone density 2, 3
• The unique feature of calcitonin is its ability to uncouple bone turnover, reducing bone resorption without necessarily affecting bone formation, potentially increasing bone mass and improving bone quality 6