Endocrine Abstracts

Introduction

Over time, different substances and protocols have been used and tested for stimulating calcitonin (CT). Some of them proved to be useful in diagnosing medullary thyroid carcinoma (MTC). However, these are associated with side-effects, with various duration, intensity and severity.

Objective

To report the side-effects observed during CT stimulation test with calcium (Ca) gluconate.

Materials and methods

A dose of 25 mg/kgBW (kilograms per body weight) of Ca gluconate was administered in 3–5 min (adjusted to the patient’s ideal weight) after informed consent, with a total of 191 explorations: 124 in women (median age = 47 ± 13.3 years, range: 21–78) and 67 in men (median age = 54 ± 13.8 years, range: 22–79). We further classified the side-effects by severity after Food and Drug Administration (FDA) 21 312.32 Code of Federal Regulations in: Adverse event (AE), Life-threatening adverse event (LTAE) and Serious adverse event (SAE).

Results

21 types of side-effects were recorded, the most frequent being warmth in 175 tests (91.62%), altered taste in 37 tests (19.37%) and bradycardia in 11 tests (5.75%). No gender significant difference was noted regarding the occurrence of side-effects in general, but men were more predisposed to experience cardio-vascular side-effects than women: bradycardia/tachycardia, hypotension/hypertension, angina, atrial/ventricular extrasystoles, asystole, P<0.02. Cardio-vascular side-effects were not correlated with values of basal CT (normal/increased) or with peak-values of stimulated CT. Regarding FDA classification of severity, amongst 191 tests: no side-effects were noted in 9 (4.71%), AE in 160 (83.76%), SAE in 22 (11.51%) and LTAE was noted only in 1 test (0.52%). There was no link between patients’ age, sex, weight or body-mass-index and severity.

Conclusion

Ca stimulation test is safe, with few mild side-effects. A specific protocol and cautions should be applied to minimize the possibility of a serious cardiac event, the most important being continuous cardiac monitoring during and after the test.