PROBLEM TO BE SOLVED : To provide novel non-toxic glutarimide derivatives which are effective in the treatment of upper respiratory tract diseases. SOLUTION : The present invention relates to novel biologically active glutarimide derivatives of general formula (I) or pharmaceutically acceptable salts thereof, their use as an agent for the treatment of upper respiratory tract diseases, pharmaceutical compositions comprising the glutarimide derivatives of general formula (I), and methods for producing the glutarimide derivatives of general formula (I) by heating a dicarboxylic acid monoamide of general formula (II) with a dehydrating agent. SELECTED DRAWING : None COPYRIGHT : (C)2019, JPO&INPIT