The effect of prednisolone on serum sodium concentration.

ABSTRACT

BACKGROUND: Glucocorticoids are widely used in clinical practice. In addition to their anti-inflammatory effects, they influence the salt and water homeostasis. Although parts of the latter action have been studied individually, there are no reports in stable outpatients on the net effect of glucocorticoids on serum sodium concentration. METHODS: A group of 23 patients on chronic prednisolone therapy was compared with a control population with respect to serum sodium concentration. Intra-individual changes in serum sodium concentration after the initiation of prednisolone therapy were studied separately in 14 patients. RESULTS: A significantly higher serum sodium level of 1.67mmol/L (P=0.03) was observed in the prednisolone-treated patients, whereas initiation of prednisolone was accompanied by an increase of 2.61mmol/L (P=0.004). The doses and duration of prednisolone therapy had no relation to the increase in serum sodium concentration. CONCLUSION: Prednisolone therapy in stable outpatients results in a small, yet significant, increase in serum sodium concentration.