Abstract: A cyclooxygenase-2-inhibitor containing as an active ingredient a compound having cyclooxygenase-2-inhibitory activity and exhibiting low toxicity that causes only minor side effects. The active compound is represented by the following formula (1) or (1′): wherein R1 represents a hydrogen atom or a C1-C3 alkyl group; R2 represents a hydrogen atom, a hydroxyl group, an organic group capable of being bound through its thiol group within the molecule, or R1 and R2 may join to each other to form a single bond; R3 represents a hydrogen atom, a halogen atom, a C1-C3 alkyl group, a C1-C3 alkoxyl group, a trifluoromethyl group, or a nitro group; each of R4 and R5, which may be identical to or different from each other, represents a hydrogen atom, a halogen atom, a C1-C4 alkoxyl group, a trifluoromethyl group, or R4 and R5 may join to each other to form a methylenedioxy group.

Abstract: A cyclooxygenase-2-inhibitor containing as an active ingredient a compound having cyclooxygenase-2-inhibitory activity and exhibiting low toxicity that causes only minor side effects.