The present invention provides compounds of the formula Ar.sup.1 --Q--Ar.sup.2 --Y--R--Z and pharmaceutically acceptable salts thereof wherein Ar.sup.1 and Ar.sup.2 are optionally substituted aryl moieties, Z is an optionally substituted nitrogen-containing moiety which may be an acyclic, cyclic or bicyclic amine or an optionally substituted monocyclic or bicyclic nitrogen-containing heteroaromatic moiety; Q is a linking group capable of linking two aryl groups; R is an alkylene moiety; Y is a linking moiety capable of linking an aryl group to an alkylene moiety and wherein Z is bonded to R through a nitrogen atom. The compounds and pharmaceutical compositions of the present invention are useful in the treatment of inflammatory diseases which are mediated by LTB.sub.4 production, such as psoriasis, ulcerative colitis, IBD and asthma.