Tox Tuesday: Cotinine/Nicotine

Right off the bat, nicotine has a few strikes against it: it is one of the most heavily used addictive drugs in the United States; 10 people die per minute due to tobacco use; and 90% of lung cancer cases in men (and 80% in women) are caused by smoking.

So why is this potentially harmful drug still so popular, even after numerous studies and statistics showing its negative side? As it turns out, people may turn to nicotine for more reasons than you think.

Nicotiana tabacum was discovered and cultivated in the Americas very early in history, around 6,000 B.C. Since its discovery, people have been smoking and chewing the leaves of the plant—but even back then, tobacco use was controversial. As early as the 1600s, How Stuff Works reports, there was speculation that there might be a link between cancer and tobacco use. Modern research has provided much more evidence of this as well.

Nicotine is an alkaloid found in the nightshade family of plants, according to Science Daily. Most people associate nicotine with tobacco, but it can also be found in lower quantities in tomato, potato, eggplant and green pepper plants as well. Nicotine is produced in plants to protect themselves from predators; humans use nicotine for the same reason in pesticides.

A similar alkaloid, cotinine, is a product or metabolite formed after nicotine enters the body. It works much in the same way as nicotine does, although in much lower potency. Cotinine is the best biomarker of exposure to tobacco smoke for active smokers and those exposed to environmental tobacco smoke.

Much of nicotine’s bad reputation comes from tobacco, and while there are over 4,000 chemicals that can be found in tobacco products (such as cigarettes), nicotine is the primary component that acts on the brain. In fact, nicotine can reach the brain within just 10 seconds of inhalation. Smokeless tobacco products, such as snuff and chewing tobacco, are of equal potency: Many can contain high levels of nicotine.

Perhaps its most dangerous quality, however, is its addictiveness, leading many smokers to regularly use the product. It is estimated that as many as 85% of adult American smokers admit to getting hooked to nicotine products under the age of 21. The Centers for Disease Control and Prevention (CDC) estimates that there were 42.1 million adult smokers in the U.S. in 2012, 33 million of which smoked every day. Nicotine is addictive for the areas of the body it affects: the adrena medulla and the central nervous system.

In the central nervous system, nicotine binds to nicotinic acetylcholine receptors releasing several neurotransmitters, like dopamine, which is what gives users that “feel good” sensation.

In the adrenal medulla, part of the adrenal gland, nicotine causes an increase of the amount of calcium infused into cells, which in turn releases the hormone epinephrine, or adrenaline. Higher blood pressure, heart rate, respiratory rate and blood sugar levels follow.

But just as it can make its users feel good, it is also toxic. A lethal dose of nicotine is 30–60 milligrams (or a drop of pure nicotine in liquid form) for an average adult. Tobacco products do not contain enough of nicotine to be fatal, when used as directed. Cigarettes contain about 10 mg, where usually only one mg is actually inhaled. For children, the lethal dose is much smaller: 10 mg.

There are many anti-smoking campaigns in the world; cigarettes can cause grave danger to the body. Smoking can harm nearly every organ in the body, and smoking causes more deaths than human immunodeficiency virus (HIV), illegal drug use, alcohol use, motor vehicle injuries and firearm-related incidents combined, according to the CDC.

E-cigarettes, introduced in the American market in 2007, aren’t much better—at least potentially. They eliminate the tar, smoke and various other chemicals found within typical cigarettes, but still contain the nicotine alongside a spritz of water vapor. At least in the United Kingdom, there is little regulation on the product, or even much studies to prove if it is safer (or worse) than its alternative. The United States does have some state and local laws prohibiting use entirely, or in certain venues. A full list of states and local communities with such prohibitions can be found here. Meanwhile, the Food and Drug Administration plans to regulate e-cigarettes, but has yet to disclose exactly how.

While cigarettes continue to have detrimental side effects, nicotine alone may be having its heyday.

In several animal and human studies recently published shows that nicotine, when delivered by gum or transdermal patch, can relieve or prevent neurological disorders (such as Parkinson’s disease, Tourette’s and schizophrenia), improve attention and focus and help with weight loss.

Apart from all of this, nicotine and tobacco products may have other personal benefits, even with their aforementioned possible side effects. Using smoking as a social activity, as a weight loss solution, for support or for when you need a break are all common personal reasons individuals give, but the reason they stay is potentially nicotine’s addictive nature. Addiction and cravings for more of the drug kick in much faster because of nicotine’s short half-life, leaving users coming back for more and more to return to that “feel good” feeling once more.

For more information on Neogen’s drug detection kits, including cotinine, click here.

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