Plasma cholinesterase activity in patients during therapy with dexamethasone or prednisone.

We have studied the effects of i.v. dexamethasone and oral prednisone on plasma cholinesterase (ChE) activity in 13 male and 10 female patients during long-term treatment with dexamethasone or prednisone. A decrease in ChE activity--probably due to inhibition of ChE synthesis in the liver--was seen in all the patients. In individual patients there was a drop in enzyme activity of 14-57% (dexamethasone) and 23-69% (prednisone) respectively, compared with individual control values. After withdrawal of dexamethasone, ChE activity in most cases increased to above control values and the period necessary for complete restoration of ChE activity was variable (between 25-70 days). Our results suggest that the decrease in ChE activity in patients treated with dexamethasone or prednisone depends on the initial dose of the drug as well as on the duration of treatment.