How does calcitonin function to alleviate pain associated with vertebral compression fractures?

From the Guidelines

Calcitonin is a crucial medication for alleviating pain associated with vertebral compression fractures, primarily through its analgesic effects on the central nervous system, and should be administered as a nasal spray (typically Miacalcin or Fortical at 200 IU daily) or as subcutaneous injections (100 IU daily) for optimal results. When considering the treatment of symptomatic osteoporotic spinal compression fractures, it is essential to prioritize the most recent and highest quality study, which in this case is the 2018 study published in the Journal of the American College of Radiology 1. This study highlights the importance of timely intervention in managing vertebral compression fractures, as most fractures show gradual improvement in pain over 2 to 12 weeks, with variable return of function.

Key Points to Consider

• Calcitonin increases endorphin levels in the brain, naturally reducing pain perception, and has anti-inflammatory properties that help decrease inflammation around the fracture site 1.
• The medication inhibits osteoclast activity, slowing bone resorption and potentially stabilizing the fractured vertebra, indirectly reducing pain by preventing further collapse 1.
• For optimal results, calcitonin therapy should be started soon after the fracture occurs and typically continues for 4-6 weeks, though some patients may benefit from treatment for up to 3 months 1.
• Patients should be aware of potential side effects, including nasal irritation from nasal calcitonin and nausea or flushing from injectable forms 1.

Comprehensive Treatment Plan

A comprehensive treatment plan should include:

• Appropriate analgesics to manage pain
• Physical therapy to support mobility and strength
• Possibly bracing to support the spine during healing
• Consideration of the patient's overall health and potential for further collapse or kyphosis, as highlighted in the 2018 study 1.

From the FDA Drug Label

Calcitonin acts primarily on bone, but direct renal effects and actions on the gastrointestinal tract are also recognized. Single injections of calcitonin cause a marked transient inhibition of the ongoing bone resorptive process. With prolonged use, there is a persistent, smaller decrease in the rate of bone resorption Histologically, this is associated with a decreased number of osteoclasts and an apparent decrease in their resorptive activity. In vitro studies have shown that calcitonin-salmon causes inhibition of osteoclast function with loss of the ruffled osteoclast border responsible for resorption of bone. Osteoporosis is a disease characterized by low bone mass and architectural deterioration of bone tissue leading to enhanced bone fragility and a consequent increase in fracture risk as patients approach or fall below a bone mineral density associated with increased frequency of fracture. Vertebral fractures occur with the highest frequency and are associated with back pain, spinal deformity and a loss of height. Calcitonin-Salmon Nasal Spray, given by the intranasal route, has been shown to increase spinal bone mass in post-menopausal women with established osteoporosis

The mechanism by which calcitonin alleviates pain associated with vertebral compression fractures is thought to be related to its ability to inhibit bone resorption and decrease the activity of osteoclasts. By reducing bone resorption, calcitonin may help to stabilize the fracture and reduce pain. Additionally, calcitonin's ability to increase spinal bone mass may also contribute to its pain-relieving effects in patients with vertebral compression fractures 2.

From the Research

Mechanism of Calcitonin in Alleviating Pain

• Calcitonin has been shown to have an analgesic effect on painful bone conditions, including osteoporotic vertebral compression fractures 3, 4, 5, 6.
• The exact mechanism of calcitonin's analgesic effect is not fully understood, but it is thought to involve the reduction of bone turnover and the inhibition of pain-producing substances 4, 6.

Efficacy of Calcitonin in Treating Vertebral Compression Fracture Pain

• Studies have demonstrated that calcitonin can provide significant pain relief for patients with acute vertebral fractures, with some studies showing a rapid onset of action and sustained pain relief for up to 4 months 3, 5, 6.
• Calcitonin has been shown to be effective in reducing pain scores in patients with osteoporotic vertebral compression fractures, with a number needed to treat of two 3.
• The efficacy of calcitonin in treating vertebral compression fracture pain is supported by multiple studies, including randomized controlled trials and systematic reviews 3, 4, 5, 6, 7.

Safety and Tolerability of Calcitonin

• Calcitonin has been shown to be safe and well-tolerated, with a low risk of adverse events, including nausea and vomiting 3, 4.
• The safety and tolerability of calcitonin make it a viable option for patients who are unable to tolerate other analgesics or who have impaired renal function 4.

Clinical Recommendations

• Calcitonin may be considered as a supplement to analgesics for the treatment of acute osteoporotic vertebral compression fracture pain, particularly in patients who are refractory to other treatments 3, 7.
• The use of calcitonin should be considered in conjunction with other non-invasive management strategies, including rest, analgesic medication, orthoses, and early mobilization 7.