Tamoxifen inhibits 5-lipoxygenase in human polymorphonuclear leucocytes

Breast cancer patient survival is increased by tamoxifen, and we therefore need to understand how this drug exerts its effect. We describe a novel action of tamoxifen, the inhibition of LTB4 and 5-HETE production from [14C]-arachidonic acid by human polymorphonuclear leucocytes.