Effect of neostigmine and pyridostigmine on the plasma cholinesterase activity

Abstract

The effect of neostigmine 0.05mg kg-1 or pyridostigmine 0.25mg kg-1 on serum cholinesterase activity was investigated in 20 adult patients undergoing elective surgery. Both drugs produced marked depression of enzymatic activity. The maximal depression was observed in samples taken 5mm after injection. The maximal percentage depression of enzymatic activity was not significantly different in the two drug groups. However, at 30-60mm after injection, the degree of depression was less in the neostigmine group. This may be attributed to the different plasma clearances of neostigmine and pyridostigmine. © 1981 Macmillian Publishers Ltd.