|Tobacco & Nicotine Addiction
|Tobacco use kills nearly half a million Americans each year, with one in every six U.S. deaths the result of smoking. Smoking harms nearly every organ of the body, causing many diseases and compromising smokers’ health in general. Nicotine, a component of tobacco, is the primary reason that tobacco is addictive, although cigarette smoke contains many other dangerous chemicals, including tar, carbon monoxide, acetaldehyde, nitrosamines, and more.
An improved overall understanding of addiction and of nicotine as an addictive drug has been instrumental in developing medications and behavioral treatments for tobacco addiction. For example, the nicotine patch and gum, now readily available at drugstores and supermarkets nationwide, have proven effective for smoking cessation when combined with behavioral therapy.
|Advanced neuroimaging technologies further assist this mission by allowing researchers to observe changes in brain function that result from smoking tobacco. Researchers have also identified new roles for genes that predispose people to tobacco addiction and predict their response to smoking cessation treatments. These findings—and many other recent research accomplishments—are affording us unique opportunities to discover, develop, and disseminate new treatments for tobacco addiction, as well as scientifically based prevention programs to help curtail the public health burden that tobacco use represents.
|When a person smokes a cigarette, the body responds immediately to the chemical nicotine in the smoke. Nicotine causes a short-term increase in blood pressure, heart rate and the flow of blood from the heart. It also causes the arteries to narrow. The smoke includes carbon monoxide, which reduces the amount of oxygen the blood can carry. This, combined with the nicotine effects, creates an imbalance between the demand for oxygen by the cells and the amount of oxygen the blood can supply.
|Cigarette smoking may increase the risk of developing hardening of the arteries and heart attacks in several ways. First, carbon monoxide may damage the inner walls of the arteries, encouraging fatty buildups in them. Over time, this causes the vessels to narrow and harden. Nicotine may also contribute to this process. Smoking also causes several changes in the blood that make clots — and heart attack — more likely.
|Symptoms of nicotine withdrawal:
- Depressed mood
- Difficulty concentrating
- Decreased heart rate
- Increased appetite or weight gain
|Nicotine does not last very long in the blood stream. From 85– 90 percent of nicotine in the blood is metabolized by the liver and excreted from the kidney rapidly. The estimated half-life for nicotine in the blood is two hours. However, smoking represents a multiple dosing situation with considerable accumulation during smoking. Therefore, it can be expected that blood nicotine would persist at significant levels for six to eight hours after smoking stopped.