Enamored, infatuated are very frequently used interchangeably, though with a loss in precision, in the sense of being passionately in love.
Enamored usually connotes complete absorption in the passion.
Infatuated , when applied to lovers and their acts, carries much the same implications as enamored but may add the implications of its primary sense (see FOND 1 ) of blind folly and unreasoning ardor.