N-substituted nicotinamide 1-oxide as histamine H2 receptor blockers

Claim 1

A N-substituted nicotinamide 1-oxide of formula ##STR22## wherein X represents a nitrogen atom or a CH group; Am represents an amino group substituted by lower alkyl, lower alkyl bearing a hydroxy or phenyl group or a cycloalkyl group of from 3 to 6 carbon atoms, or by a radical selected from the group consisting of lower alkenyl, lower alkynyl, phenyl and cycloalkyl of from 3 to 6 carbon atoms; an amino group substituted by two identical or different lower alkenyl or lower alkynyl groups; an amino group substituted by two identical or different (hydroxy)lower alkyl or (lower alkoxy)lower alkyl groups; a lower dialkylamino group; a lower dialkylamino group substituted by a phenyl, cycloalkyl of from 3 to 6 carbon atoms, methoxy or hydroxy group; a pyrrolidino group; a morpholino group; a thiomorpholino group; a hexamethyleneimino group; a piperidino group; a piperidino group substituted by a methyl, hydroxy or hydroxymethyl group or by two methyl groups; a piperazino group substituted in the 4-position by a lower alkyl group or a (hydroxy)lower alkyl group; a piperazino group substituted in the 4-position by a lower alkyl group or a (hydroxy)lower alkyl group and also bearing a methyl group in the 3- and/or 5-position; or a pharmaceutically acceptable acid addition salt thereof.