The invention relates to compounds of formula (I) and pharmaceuticallyacceptablederivatives thereof:(see formula I)where Ar1, Ar2, W, X, R3 and R4 have prescribed meanings. The invention alsorelates tocompositions comprising an effective amount of a compound of formula I or apharmaceuticallyacceptable derivative thereof and to use for treating or preventing acondition such as pain, UI,an ulcer, IBD and IBS, comprising administering to an animal in need thereofan effectiveamount of a compound of formula I or a pharmaceutically acceptable derivativethereof.
