Effect of nonsteroidal antiinflammatory drugs on human monocyte chemotaxis in vitro

Human blood monocytes were incubated in vitro with ibuprofen, naproxen, and indomethacin at clinically relevant concentrations and were subsequently tested for chemotactic responsiveness in a modified Boyden chamber with zymosan-activated serum as the chemotactic agent. Ibuprofen and naproxen inhibited monocyte chemotaxis at concentrations above 25 micrograms/ml. The inhibition was dose dependent and a 50% inhibition (ID50) was seen at 70 and 62 micrograms/ml, respectively. Indomethacin inhibited monocyte chemotaxis at concentrations above 1 microgram/ml, but never reached ID50. It is concluded that the suppression of blood monocyte migration (ID50) is not a general property of all nonsteroidal antiinflammatory drugs.