Certain new diphenylpropenamides having a carboxyalkanamido or a carboxyalkenamido group on one of the phenyl rings and their use for antagonizing the spasmogenic activity of the slow-reacting substance of anaphylaxis (SRS-A) in a human subject. In particular, the compounds of the invention are useful for preventing and treating certain obstructive airways diseases, notably allergic bronchial asthma, allergic rhinitis and certain skin disorders, in human subjects.