Abstract: Compounds of Formula (I), and salts and prodrugs thereof, wherein R.sup.1 represents H, optionally substituted C.sub.1-6 alkyl or C.sub.3-7 cycloalkyl; R.sup.2 is NHR.sup.12 or (CH.sub.2).sub.s R.sup.13 where 5 is 0, 1 or 2; R.sup.3 represents C.sub.1-6 alkyl, halo or NR.sup.6 R.sup.7 ; R.sup.4 and R.sup.5 are H, C.sub.1-12 alkyl optionally substituted by NR.sup.9 R.sup.9' or an azacyclic or azabicyclic group, optionally substituted C.sub.4-9 cycloalkyl, C.sub.4-9 cycloalkyl C.sub.1-4 alkyl, aryl, arylC.sub.1-6 alkyl or azacyclic or azabicyclic groups, or R.sup.4 and R.sup.5 together form the residue of an optionally substituted azacyclic or azabicyclic ring system; x is 0, 1, 2 or 3; R.sup.12 is optionally substituted phenyl or pyridyl; R.sup.13 represents a group (A) wherein R.sup.14 is H or C.sub.1-6 alkyl; R.sup.15 is H, C.sub.1-6 alkyl, halo or NR.sup.6 R.sup.7 ; and the dotted line is an optional covalent bond; are CCK and/or gastrin antagonists useful in therapy.