Benzodiazepine derivatives and their use as antagonists of cholecystokinin and/or gastrin receptors

A compound of formula (I), or a salt or prodrug thereof:

• ##STR16## wherein:
• each of W and Z represents a nitrogen atom or a group CH;
• one of X and Y represents a carbonyl group and the other represents a group NH, with the proviso that the system W-X-Y-Z contains no nitrogen-nitrogen bonds;
• R.sup.1 represents H, C.sub.1-6 alkyl, C.sub.3-7 cycloalkyl, cyclopropylmethyl, (CH.sub.2 ).sub.q -imidazolyl, (CH.sub.2).sub.q triazole, (CH.sub.2).sub.q tetrazole (where q is 1, 2 or 3 ), CH.sub.2 CO.sub.2 R.sup.5 (where R.sup.5 is C.sub.1-4 alkyl) or CH.sub.2 CONR.sup.6 R.sup.7 (where R.sup.6 and R.sup.7 each independently represents H or C.sub.1-4 alkyl, or R.sup.6 and R.sup.7 together form a chain (CH.sub.2).sub.p where p is 4 or 5);
• R.sup.2 represents C.sub.1-6 alkyl, halo, (CH.sub.2).sub.r -tetrazolyl, optionally substituted in the tetrazolyl ring by C.sub.1-4 alkyl, (CH.sub.2).sub.r -triazolyl, (CH.sub.2).sub.r -imidazolyl, CONR.sup.6 R.sup.7, SO(C.sub.1-6 alkyl), SO.sub.2 (C.sub.1-6 alkyl), CONHSO.sub.2 R.sup.8, SO.sub.2 NHCOR.sup.8 (where R.sup.8 is C.sub.1-6 alkyl, optionally substituted aryl, 2,2-difluorocyclopropane or trifluoromethyl), SONHR.sup.9 (where R.sup.9 is a nitrogen containing heterocycle), cyano, B(OH).sub.2 or (CH.sub.2).sub.r CO.sub.2 H, where r is zero, 1 or 2;
• R.sup.3 represents C.sub.1-6 alkyl or halo;
• m is 0, 1 or 2;
• and
• n is 0, 1, 2 or 3.