A P2X
4
receptor antagonist is a compound represented by the formula (I) or a pharmacologically acceptable salt thereof, which is used as a preventive or therapeutic agent for neuropathic pains:
Wherein B is aryl or the like that can have a substituent; Y is C
1-5
alkylene that can have a double bond; Z is O, S or the like; each of R
1
, R
2
and R
3
independently is hydrogen, C
1-8
alkyl or the like; R
4
is hydrogen, C
1-8
alkyl or the like; each of P and Q independently is hydrogen, halogen, C
1-8
alkyl or the like; W is C
1-8
alkyl or the like; and each of n and m independently is 1 or 2.