Abstract: The present invention provides a protective agent for retinal nerve or optic nerve which exerts its effect through a different mechanism from that of conventional therapeutic agents and can be taken for long periods. The present invention is the protective agent for retinal nerve or optic nerve which comprises a compound with aldose reductase inhibiting activity such as the compound represented by the following general formula as an active ingredient. A preferable compound thereof is (2S,4S)-6-fluoro-2?,5?-dioxospiro[chroman-4,4?-imidazolidine]-2-carboxamide: wherein X represents a halogen atom or a hydrogen atom, R1 and R2 independently represent a hydrogen atom or an optionally substituted C1 to C6 alkyl group, or R1 and R2, together with a nitrogen atom bound thereto, or optionally another nitrogen atom or an oxygen atom, are combined to form a 5- to 6-membered heterocycle.

Abstract: The present invention provides a protective agent for retinal nerve or optic nerve which exerts its effect through a different mechanism from that of conventional therapeutic agents and can be taken for long periods. The present invention is the protective agent for retinal nerve or optic nerve which comprises a compound with aldose reductase inhibiting activity such as the compound represented by the following general formula as an active ingredient. A preferable compound thereof is (2S,4S)-6-fluoro-2?,5?-dioxospiro[chroman-4,4?-imidazolidine]-2-carboxamide: wherein X represents a halogen atom or a hydrogen atom, R1 and R2 independently represent a hydrogen atom or an optionally substituted C1 to C6 alkyl group, or R1 and R2, together with a nitrogen atom bound thereto, or optionally another nitrogen atom or an oxygen atom, are combined to form a 5- to 6-membered heterocycle.

Abstract: Novel heterodimers of tetrahydroacridines and tetrahydroquinolinones are disclosed. The heterodimers are capable of acting as both acetylcholinesterase inhibitors and N-methyl-D-aspartate (NMDA) receptor antagonists. The heterodimers may be used to improve cognitive defects via treatment or prevention in both humans and non-humans.

Abstract: The present invention provides a preventive or therapeutic agent for cerebral ischemic injury or cerebral ischemic reperfusion injury in stroke such as cerebral infarction and cerebral hemorrhage which exerts its effect through a different mechanism from that of conventional therapeutic agents and can be taken for along period. The present invention is a preventive or therapeutic agent for cerebral ischemic injury or cerebral ischemic reperfusion injury in stroke which contains 6-fluoro-2?,5?-dioxospiro[chroman-4,4?-imidazolidine]-2-carboxamide as an active ingredient. A particularly preferable compound is an optically resolved (2S,4S)-form of fidarestat.

Abstract: Novel heterodimers of tetrahydroacridines and tetrahydroquinolinones are disclosed. The heterodimers are capable of acting as both acetylcholinesterase inhibitors and N-methyl-D-aspartate (NMDA) receptor antagonists. The heterodimers may be used to improve cognitive defects via treatment or prevention in both humans and non-humans.