The non-steroidal anti-inflammatory drugs, flufenamic acid, mefenamic acid and niflumic acid, block Ca2+-activated non-selective cation channels in inside-out patches from the basolateral membrane of rat exocrine pancreatic cells. Half-maximal inhibition was about 10 μM for flufenamic acid and mefenamic acid, whereas niflumic acid was less potent (IC50 about 50 μM). Indomethacin, aspirin, diltiazem and ibuprofen (100μM) had not effect. It is concluded that the inhibitory effect of flufenamate, mefenamate and niflumate is dependent on the specific structure, consisting of two phenyl rings linked by an amino bridge.
