A compound represented by formula (I) ##STR00001## 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.