We now know that cigarettes are addictive, and that nicotine is the drug in tobacco that causes addiction to nicotine, but it is the over 4000 other chemicals in cigarette smoke that cause the most harm. This combination makes cigarettes deadly.
When smokers who are addicted to cigarettes quit smoking, 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.