A compound represented by formula (I) wherein the symbols in the formula
are the same meanings as those in specification, salts thereof, solvates
thereof, or prodrugs thereof binds to DP receptor and shows antagonistic
activity for DP receptor. Thus, it is useful for prevention and/or
treatment of diseases such as allergic disease (e.g., allergic rhinitis,
allergic conjunctivitis, atopic dermatitis, bronchial asthma and food
allergy), systemic mastocytosis, disorders accompanied by systemic mast
cell activation, anaphylaxis shock, bronchoconstriction, urticaria,
eczema, diseases accompanied by itch (e.g., atopic dermatitis and
urticaria), diseases (e.g., cataract, retinal detachment, inflammation,
infection and sleeping disorders) which is generated secondarily as a
result of behavior accompanied by itch (e.g., scratching and beating),
inflammation, chronic obstructive pulmonary diseases, ischemic
reperfusion injury, cerebrovascular accident, chronic rheumatoid
arthritis, pleurisy, ulcerative colitis, etc. Since it specifically binds
to DP receptor and binds weakly to other prostaglandins receptors, they
can be pharmaceuticals having little side effect.