High dose intravenous methylprednisolone pulse therapy causes transient increase of serum calcium and phosphate levels.
High and very high doses of intravenous methylprednisolone (IVMP) administered in pulses are the first-line treatment for active, moderateto- severe, as well as sight-threatening Graves' orbitopathy (GO). However, glucocorticoid therapy is associated with side effects, among others, it affects bone metabolism.


AIM
The aim of study was to assess the acute effects of high and very high doses of IVMP on calcium (Ca) and phosphate (P) balance in euthyroid patients with moderate-to-severe GO and sight-threatening GO due to dysthyroid optic neuropathy (DON).


MATERIALS AND METHODS
Thirty-six patients with active, moderate-tosevere GO were treated with twelve once-weekly pulses (with cumulative dose of 4.5 g IVMP) and 11 patients with DON received 3 intravenous pulses of 1.0 g IVMP on three consecutive days. We measured serum levels of Ca and P at baseline and on the following days after the beginning of the IVMP therapy.


RESULTS
We observed a significant increase in serum Ca level on the next day after the 1st IVMP pulse both in patients with moderate-tosevere GO and with DON. Then, on the day 3, the decrease of serum Ca was noticed. In patients with moderate-to-severe GO, on the day 2 serum P showed a significant increase and then, it returned to basal level on the day 3.


CONCLUSIONS
We observed a significant increase in serum Ca level on the next day after the 1st IVMP pulse both in patients with moderate-tosevere GO and with DON. Then, on the day 3, the decrease of serum Ca was noticed. In patients with moderate-to-severe GO, on the day 2 serum P showed a significant increase and then, it returned to basal level on the day 3.