Lunesta (eszopiclone) is a sedative, also called a hypnotic. It affects chemicals in your brain that may be unbalanced in people with sleep problems (insomnia). Some people using this medicine have engaged in activity such as driving, eating, or making phone calls and later having no memory of the activity. If this happens to you, stop taking Lunesta and talk with your doctor about another treatment for your sleep disorder. Lunesta can cause sie effects that may impair your thinking or reactions. You may still feel sleepy the morning after taking the medication. Until you know how this medication will affect you during waking hours, be careful if you drive, operate machinery, pilot an airplane, or do anything that requires you to be awake and alert. Do not drink alcohol while you are taking this medication. It can increase some of the side effects, including drowsiness. Lunesta may be habit-forming and should be used only by the person it was prescribed for. Lunesta should never be shared with another person, especially someone who has a history of drug abuse or addiction. Keep the medication in a secure place where others cannot get to it.