There are some special problems that may occur while taking sleeping pills. Memory problems: Sleep medicines may cause a special type of memory loss or “amnesia.” When this occurs, a person may not remember what has happened for several hours after taking the medicine. This is usually not a problem since most people fall asleep after taking the medicine. Memory loss can be a problem, however, when sleep medicines are taken while traveling, such as during an airplane flight and the person wakes up before the effect of the medicine is gone. This has been called traveler’s amnesia.Memory problems are not common while taking Ambien in most instances memory problems can be avoided if you take Ambien only when you are able to get a full night’s sleep (7 to 8 hours) before you need to be active again. Be sure to talk to your doctor if you think you are having memory problems. Tolerance: When sleep medicines are used every night for more than a few weeks, they may lose their effectiveness to help you sleep. This is known as “tolerance.’’ Sleep medicines should, in most cases, be used only for short periods of time, such as 1 or 2 days and generally no longer than 1 or 2 weeks. If your sleep problems continue, consult your doctor.