To Your Health
Is salmon calcitonin as worrisome as Fosamax?
A. Since 1995 Fosamax (a brand name for alendronate) has been used in the treatment of osteoporosis. Because this medicine tends to upset the stomach and is poorly absorbed, people should take alendronate with a glass of water first thing in the morning, then drink another glass of water and not lie down for at least 30 minutes.
Salmon calcitonin (often termed "calcitonin salmon" and for some reason sold under the brand name Miacalcin) is a hormone that is often used, along with Fosamax, as part of the treatment for osteoporosis. Calcitonin slows down the rate at which old bone is broken down, called resorption. Resorption (removal) of old bone is necessary before new, strong bone can take its place. Calcitonin can increase bone density in the spine and in some cases relieve the pain of spinal fractures. It reduces the risk of spinal fractures but does not appear to reduce the risk of fractures in other parts of the body.
Calcitonin was originally developed to treat Paget's disease, which is characterized by excessive breakdown of bone followed by abnormal bone formation. The new bone in Paget's disease is weakened, structurally enlarged or misshapen, and filled with new blood vessels. These bones can be painful when they press on neighboring nerves and may fracture easily.
Calcitonin salmon is not derived from salmon but is made synthetically, patterned after the calcitonin made by salmon. Ordinarily, pig hormones resemble human hormones most closely, but in this case the salmon form seems to be more potent. Calcitonin salmon appears to have longer-lasting effects and is thus more suitable for long-term therapy than the form found in pigs.
In humans, cells imbedded in the thyroid gland make calcitonin. Factors that regulate our synthesis and secretion of calcitonin are very poorly understood. A number of other hormones, as well as input from the nervous system, have been shown to stimulate calcitonin release. Calcitonin seems to play a minor role in regulating blood concentrations of calcium and phosphorus, although humans with chronically increased or decreased blood levels of calcitonin do not show abnormal serum calcium levels.
Side effects from calcitonin salmon are not common, but some people experience reactions similar to allergy: difficulty breathing, swelling, hives, chest pressure, upset stomach, hot flashes, headache, nasal congestion, dizziness, weakness, or chills. Prolonged use of calcitonin salmon may lead to the development of anti-calcitonin antibodies, making the treatment worthless.
Calcitonin salmon does not reduce the serum calcium levels below normal in women with postmenopausal osteoporosis, but it has been shown to reduce the magnesium in some cases, so a magnesium supplement when using calcitonin salmon is prudent. Other than the rare allergic response, calcitonin salmon appears to be a valuable aid in the management of osteoporosis.
Although there is no data about the effectiveness of adding calcitonin to estrogen therapy, it is a safe alternative to estrogen for women who cannot or will not take estrogen for osteoporosis.