Use of linear annelated tricyclics as inhibitors of erythrocyte aggregation

Use of linearly fused tricyclic compounds of general formula I.in which R represents an optionally substituted phenyl ring or an optionally substituted heterocyclic five - membered ring containing from 1 to 4 heteroatoms, wherein the heteroatoms may be the same or different and denote oxygen, sulfur or nitrogen and, if desired, at one or several nitrogen atoms can carry one oxygen atom,or in the event that X represents a bond, R, in addition to the abovementioned groups, also a hydrogen atom, an alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, haloalkyl, alkoxyalkyl, carboxyalkyl, alkoxy, carbonylalkyl, a hydroxy, mercapto, amino, alkylmercapto,Formylaminoalkyl, or a pyridylcarbonylamino group,X represents a bond, an alkylene, or the vinylene group,A may be a nitrogen atom or the group CRs, where R5 represents a hydrogen atom, an alkyl, alkenyl, cycloalkyl, cycloalkenyl, cyano, alkylcarbonyl, alkoxycarbonyl, carboxy, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl or aryl group,B is an oxygen atom, a sulfur atom or the group NR6 means, wherein R6 is a hydrogen atom or an alkyl group, or B is the group CR7R8th can be, where R7 represents a hydrogen atom, an alkyl, alkenyl, or a cycloalkyl group, and R8th a hydrogen atom, an alkyl, alkenyl or cyano group, a carbonyl group substituted by a hydroxy, alkyl, alkoxy, amino, alkylamino, dialkylamino or hydrazino group, or R7 and R8th together form an alkylidene or cycloalkylidene group, or R7 and R8th together with the carbon atom to which they are attached form a spirocycle,and their pharmacologically acceptable salts for the treatment of diseases in which the erythrocyte aggregation plays an important role in the pathogenesis.