Hofer, M., Pospisil, M., Dugek, L., Hoferova, Z. and Weiterova, L. A Single Dose of an Inhibitor of Cyclooxygenase 2, Meloxicam, Administered Shortly after Irradiation Increases Survival of Lethally Irradiated Mice. Radiat. Res. 176, 269-272 (2011). This study extends earlier findings of the authors demonstrating that meloxicam, a selective inhibitor of cyclooxygenase 2, supports hematopoietic recovery in sublethally irradiated mice and is radioprotective when given before irradiation. We report here that when meloxicam was administered in a single dose 1 h after a lethal 9-Gy whole-body dose, an increased 30-day survival was achieved. Additional studies showed that administration of meloxicam 24 h after lethal irradiation is ineffective and its repeated administration deleterious. Possible mechanisms of the therapeutic effects of meloxicam administered early after irradiation are discussed. (C) 2011 by Radiation Research Society