Lunesta is a sedative, also called a hypnotic. It affects chemicals in your brain that may become unbalanced and cause sleep problems (insomnia).

Lunesta is used to treat insomnia. This medication causes relaxation to help you fall asleep and stay asleep.

Lunesta may also be used for purposes other than those listed in this medication guide.

Most important: Lunesta may cause a severe allergic reaction. Stop taking Lunesta and get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Lunesta will make you fall asleep. Never take this medication during your normal waking hours, unless you have at least 8 hours to dedicate to sleeping.

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 side 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 of Lunesta, 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.

You may have withdrawal symptoms if you stop taking this medication after taking it over several days in a row. Do not stop taking Lunesta suddenly without first talking to your doctor. You may need to use less and less before you stop the medication completely.