The present invention provides a compound of formula (I) ##STR00001## or its salts or pharmaceutically acceptable derivatives thereof wherein; X.sub.1 is selected from a group consisting of CH.sub.2, C(.dbd.O), C(.dbd.NH), NC(.dbd.O), R.sub.1 is selected from the group consisting of optionally substituted arylalkyl, and optionally substituted heteroarylalkyl R.sub.2 is selected from the group consisting of optionally substituted alkyl, optionally substituted aryl or heteroaryl or NR.sub.24R.sub.25 R.sub.3 is selected from the group consisting of hydrogen, halogen, hydroxyl, alkoxy, aryloxy, optionally substituted alkyl, optionally substituted amino, optionally substituted amino sulfonyl or nitrile; R.sub.4 is selected from the group consisting of optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted heterocycloalkyl, optionally substituted acyl, optionally substituted sulfonyl, optionally substituted sulfamoyl, optionally substituted aryl, optionally substituted arylalkyl, and optionally substituted heteroaryl R.sub.5 may be hydrogen, an optionally substituted alkyl, preferably CH.sub.3 or, NR.sub.4R.sub.5 may form an optionally substituted saturated or partially saturated 4-7 membered ring with the general formula (II). ##STR00002## Wherein; X.sub.2 is C(.dbd.O), CH.sub.2, CH(R.sub.6) or C(R.sub.6)(R.sub.6), X.sub.3 is CH.sub.2, CH(R.sub.7), C(R.sub.7)(R.sub.7), NH, N(R.sub.8), O or S Each R.sub.6 independently represents optionally substituted amino, optionally substituted amino carbonyl, hydroxyl, optionally substituted acyl, optionally substituted alkoxy, optionally substituted aryloxy, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted arylalky, optionally substituted aryl or optionally substituted heteroaryl; Each R.sub.7 independently represents optionally substituted amino, optionally substituted amino carbonyl, hydroxyl, optionally substituted acyl, optionally substituted alkoxy, optionally substituted aryloxy, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted arylalky, optionally substituted aryl or optionally substituted hetero aryl R.sub.8 is optionally substituted acyl, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted arylalkyl, optionally substituted aryl or optionally substituted heteroaryl; R.sub.24 and R.sub.25 are the same or different and each represents hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted arylalkyl, optionally substituted aryl or optionally substituted heteroaryl, n=1 or 2 m=1, 2 or 3 With the proviso that when X.sub.1 is C.dbd.O and R.sub.5 is H then R.sub.4 is not: ##STR00003## Or ##STR00004## Or ##STR00005## Where R.sub.4a, R.sub.5a and R.sub.6a are each independently H, C.sub.1-6alkyl, aryl, heteroaryl, cycloalkyl, or aryl-C.sub.1-6alkyl; R.sub.10a is H or C.sub.1-6alkyl; and R.sub.11a is C.sub.1-6alkyl or aryl-C.sub.1-6alkyl and when X.sub.1 is C.dbd.O or CH.sub.2 and R.sub.5 is H then R.sub.4 is not: ##STR00006## Where q is 0 to 5, R.sub.3b is H, OH or alkoxy and R.sub.4b is NH.sub.2, phenyl or a C.sub.3-10 heterocycle. The compounds are useful as potassium ion channel inhibitors.