The present invention relates compounds of the formula (I); wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, and R.sup.10 represent a variety of substituents; A represents NR.sup.9 or O; B represents a bond, CH.sub.2, NR.sup.9 or O, wherein one or both hydrogen atoms in said CH.sub.2 moiety may be replaced with one or both of R.sup.7 and R.sup.8, or alternatively, one of the hydrogen atoms in said CH.sub.2 moiety together with a hydrogen atom from an adjacent carbon are replaced by a double bond; with the proviso that when A is O, then B is NR.sup.9; n is zero, 1 or 2; and pharmaceutically acceptable salts thereof. The compounds are of particular use in the treatment or prevention of depression, anxiety, pain, inflammation, migaine, emesis or postherpetic neuralgia ##STR00001##