Abstract: The use of a compound of formula I ##STR1## wherein R is a hydrogen atom or a group selected from C.sub.1-6 alkyl (optionally substituted by C.sub.3-7 cycloalkyl), C.sub.3-6 alkenyl, C.sub.3-6 alkynyl, C.sub.3-7 cycloalkyl, aralkyl (in which the alkyl moiety contains 1-5 carbon atoms) and --CHO;R.sup.1 and R.sup.2, which may be the same or different, represent a hydrogen atom, a halogen atom or a group selected from C.sub.1-4 alkyl, C.sub.1-4 alkoxy, hydroxyl, cyano, nitro and --NR.sup.3 R.sup.4 where R.sup.3 and R.sup.4 is each a hydrogen atom or a C.sub.1-4 alkyl group andX is an oxygen atom or a group --CH.sub.2- ; or a physiologically acceptable salt or hydrate thereof for treating, relieving or preventing the effects of sexual dysfunction.Preferred compounds include trans-5-fluoro-2,3,3a,9a-tetrahydro-1H-[1,4] benzodioxino [2,3-c]pyrrole and trans-5-fluoro-1,2,3,3a,9,9a-hexahydro[1] benzopyrano [2,3-c]pyrrole.