Ambien (generic name: zolpidem) is primarily prescribed for the short-term treatment of insomnia, particularly for those who have difficulty falling asleep. It works by slowing down brain activity to allow sleep to occur. Ambien is most commonly prescribed for people who have trouble falling asleep (sleep-onset insomnia). Extended-release forms of Ambien, such as Ambien CR, are designed to help people stay asleep throughout the night, in addition to helping them fall asleep.