Effects of isoxicam and other non-steroidal anti-inflammatory drugs on arachidonic acid metabolism by rat peritoneal leucocytes.

Inhibition of prostaglandin formation from [14C]arachidonic acid by rat peritoneal leucocytes occurred with nonsteroidal anti-inflammatory drugs, their order of potency being indomethacin greater than piroxicam greater than naproxen greater than ibuprofen greater than isoxicam. At the lowest concentration tested (1 microgram ml-1), indomethacin markedly increased the accumulation of lipoxygenase products in the cell incubates. Naproxen, ibuprofen or piroxicam 1 or 10 micrograms ml-1 resulted in smaller increases of lipoxygenase products, and there was only a small rise with these concentrations of isoxicam.