TABLE 9

IC50 values for acetaminophen and naproxen in CHIM isolated from human donors 1 (duodenum, jejunum, and ileum), 2 (duodenum and jejunum), and 3 (combination of all three small intestine regions)

DrugIC50
DuodenumJejunumIleum
mM
Acetaminophen2.251.221.20
Naproxen0.35*0.39*0.36*
IC50 ratio6.363.093.35
  • The IC50 ratio was calculated by dividing the IC50 for acetaminophen by that for naproxen. The results show that naproxen was consistently more cytotoxic than acetaminophen for all three regions of the small intestine.

  • * P < 0.05 (asterisks represent IC50 values obtained from naproxen that are significantly different from those obtained for acetaminophen).