“In vitro addition of cimetidine also produced significant inhibition of enzymes, the inhibition constant (Ki) for sucrase, lactase , maltase and alkaline phosphatase being 22.8, 4.5, 11.5 and 4.8 mM, respectively.”
“It was further observed that in vitro addition of cimetidine also decreased Vmax in case of maltase, sucrase and lactase , Km was unchanged, whereas in case of alkaline phosphatase there was a decrease in Vmax and increase in Km, as compared to the controls.”