Meclofenamate sodium monohydrate inhibits chemotactic factor-induced human polymorphonuclear leukocyte function. A possible explanation for its antiinflammatory effect.

Meclofenamate sodium monohydrate (MSM), a potent nonsteroidal antiinflammatory agent, specifically inhibits chemotactic factor-induced human polymorphonuclear leukocyte functions: chemotaxis, degranulation, and generation of superoxide anion radicals. These effects of MSM were found to be dependent upon the concentrations of drug not bound to albumin (free drug), and were caused by its ability to interfere at both a receptor and post-receptor (i.e., a step distal to mobilization of polymorphonuclear leukocyte intracellular Ca2+) level. These unique actions of MSM may provide a partial explanation for its potent antiinflammatory effect.