The present invention relates to novel quinazoline derivatives with less skin irritation and an excellent action of strongly suppressing scratching behavior, and pharmaceutical compositions containing a quinazoline derivative as an active ingredient. The present invention is directed to the quinazoline derivatives represented by the general formula [1] or pharmaceutically acceptable salts thereof. In the general formula [1], R1 represents hydrogen or the like； R2 represents hydrogen or the like； R3 and R4 are the same or different and represent hydrogen, alkyl, alkoxy or halogen； R5 is combined with R6 to represent alkylene or represents hydrogen, hydroxy, alkyl, phenyl or alkoxy； R6 represents alkyl, cycloalkyl, phenyl, a 5- to 10-membered aromatic heterocyclic group containing one to three heteroatoms selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom, or —N(R6-1)(R6-2).
