PHARMACEUTICAL COMPOSITIONS CONTAINING COMPOUNDS HAVING ACTION ON HISTAMINE RECEPTORS

Compounds of general formula (I)and physiologically acceptable salts and hydrates thereof in whichR1 and R2 each represent methyl groups or together with the nitrogen atom to which they are attached form a pyrrolidino, piperidino or hexamethylenimino group;R3 represents hydrogen or methyl;Alk represents a straight or branched alkylene chain of 1 to 6 carbon atoms;R4 represents a hydrogen atom and R5 represents a C1-4 alkyl group; or R4 and R5 together with the atoms to which they are attached form a tetrahydropyranyl ring; andeither n is zero, X is oxygen, m is 3 or 4, and Q is a benzene ring linked through the 1- and 3- positions;or n is 1, X is sulphur, m is 2, and Q is a furan ring linked through the 2- and 5- positions with optionally a methyl substituent on the carbon atom adjacent to the group R1R2NCH2, or Q is a thiophene ring linked through the 2-and 4- positions with the group R1R2NCH2 in the 2- position;with the proviso that when Q is other than a benzene ring, R1 and R2 are methyl groups,are disclosed as having action as histamine H2- antagonists.