The Three Stigmata of Palmer Eldritch Novel

In the overcrowded world and cramped space colonies of the late 21st century, tedium can be endured through the use of the drug Can-D, which enables the users to inhabit a shared illusory world. When industrialist Palmer Eldritch returns from an intersteller trip, he brings with him a new alien drug Chew-Z, which is far more potent than Can-D, but threatens to plunge the world into a permanent state of drugged illusion controlled by the mysterious Eldritch.