Calcium and phosphorus metabolism during methylprednisolone puls therapy

  intravenous glucocorucoid pulse therapy is a common treatment for immunologically origin diseases but it can not be considered a completely bening treatment.the effects of long term administration of glucocorticoids on calcium and phosphorus metabolism are week known ,but is less in known about the effect of pluse therapy.the purpose of this study was to investigate the effect of methylprednisolone pulse therapy on serum and uninary calcium and phosphorus and serum parathormone,in this prospective study 40 patients who received methylprednisolone puls therapy fot different,reasons were investigated.patients with renal insufficiency and those taking medications affecting calcium and  phosphorus metabolism were excluded.serum calcium,phosphorus,parathormone,creatining and urinary calcium,phosphorus,and creatinine were measured before pulse therapy and in three consecutive days after treatment.this intervention had no effect on serum calcium,parathormone and urinary calcium.serum phosphorus decreased with a nadir on the second day and urinary phosphorus increased. it was concluded that glucocorucoid pulse therapy directly increases renal phosphorus excretion,but calcium metabolism is not disturbed.