We now know that cigarettes are addicting, and that nicotine is the drug in tobacco that causes addiction. Smokers are compelled to smoke by this addiction to nicotine, but it is the 4,000+ other chemicals in cigarette smoke that cause the most harm. This combination makes cigarettes deadly.

What is it About Nicotine?

When you smoke, nicotine enters the bloodstream through the lungs. It quickly reaches the brain, where it affects certain chemicals that change the way you feel. Eventually, the brain becomes dependent on nicotine to control these chemicals that make you feel "normal".

Am I Addicted?

You may be addicted to nicotine if you experience one or more of the following signs:

• You continue to smoke despite the desire to quit.
• You have made a serious, but unsuccessful, attempt to stop using tobacco or permanently reduce the amount you use.
• Your attempts to stop smoking have led to physical withdrawal symptoms (including a craving for tobacco, anxiety, irritability, restlessness, difficulty in concentrating, headaches, drowsiness and stomach upset).
• You develop a "tolerance" to tobacco. Smoking the same number of cigarettes produces less effect over time, making it necessary to increase the number of cigarettes you smoke to achieve the desired sensation.
• You have continued to use tobacco even when you have a serious physical problem (such as cardiovascular or respiratory disease) that you know is worsened by tobacco.

Withdrawal

When smokers who are addicted to nicotine quit smoking (and, as a result, quit taking nicotine into their bodies), they may suffer from symptoms that can be psychological, emotional, or physical in nature. This is called withdrawal. They may experience irritability, anxiety, difficulty concentrating, restlessness or depression. Fortunately for many patients, ZYBAN reduces withdrawal symptoms and the urge to smoke.