Evidence of systemic allergic reactions is minimal and no anaphylactic reaction has been reported. In approximately one half the patients tested after 6 months or more of treatment, indications of circulating antibodies to calcitonin were obtained. In most of the patients the level of antibodies was not high enough to interfere with the effect of exogenous calcitonin. In a few patients, resistance to calcitonin was attributed to high levels of antibodies. Secondary hyperparathyroidism as a result of the transient hypocalcemia following calcitonin administration did not develop in patients with Paget's disease.
Calcitonin administration can lead to antibody development.
This is minimal when the hormone is injected in the absence of an adjuvant or when it is not complexed with a larger protein. Gelatin and acetate buffer solutions have been shown to have little or no adjuvant like action in comparison to Freund's adjuvant. The antibodies which develop when calcitonin is administered repeatedly with Freund's adjuvant are measurable in the circulation by radio-immunoassay techniques. In no instance has any systemic allergic or anaphylactic effect been reported in animal studies with calcitonin, in spite of the known development of circulating antibodies. Supportive treatment may be indicated.