Dangers of nicotine

Nicotine replacement products are the most common form of over-the-counter products used to help quit smoking. Per their name, they contain nicotine and therefore maintain dependence.

Nicotine is a toxic and addictive alkaloid found in the tobacco plant. Due to its characteristics, in addition tobacco and nicotine replacement products, it is used in insecticides.

Effects of nicotine on the body

Nicotine is a neurotoxin. It causes increased heart rate, blood pressure and contraction of the heart, superficial veins and coronary arteries. As a result, the heart is strained and the risk of heart attack is elevated.

As nicotine use develops a tolerance to the toxin, increasingly large doses are needed to satisfy the symptoms of addiction, resulting in a cycle of dependence. Tobacco use disorder refers to a disorder resulting from physical, psychological and social dependence caused by smoking.

Nicotine dependence refers to the change in the amount and function of nicotine receptors in the central nervous system as a result of nicotine use that lead to physical withdrawal symptoms when the person stops smoking. In terms of its pharmacological and behavioural factors, nicotine dependence is similar to other substance dependencies.

According to international psychiatric classification, nicotine dependence meets the criteria of a chemical dependence. The key mechanisms involved in the development of nicotine dependence are increased tolerance in the central nervous system, nicotine metabolism in the liver, and genetic factors that regulate these. In young persons, the effects of nicotine on brain activity are particularly significant. Nicotine dependence develops quickly, but there exist individual differences that are affected by several genetic and environmental factors. While the nicotine contained in cigarettes, snus and other tobacco products is the most important substance in causing dependence, tobacco smoke also contains other chemicals that affect the development of dependence.

As the body’s tolerance to nicotine increases, the risk of developing type 2 diabetes is elevated. Nicotine is also detrimental to the function of endothelial cells in blood vessels.

Toxicity of nicotine

When ingested in large amounts, nicotine paralyses the nervous system and results in poisoning. In children, eating a single cigarette may result in nicotine poisoning. The liquid cartridges in electronic cigarettes have caused instances of fatal poisoning in children. Even for adults, the absorption of just 60 mg of nicotine in the body may be fatal for a person without previous exposure to nicotine. This amount corresponds to 30-40 cigarettes of 2-4 electronic cigarette cartridges.

Nicotine in tobacco and nicotine replacement products

The highest concentrations of nicotine are found in tobacco products, such as cigarettes, snus and electronic cigarettes. The nicotine content of e-cigarettes may vary. In a comparison of 11 products, the nicotine content ranged from 0 to 35 micrograms of nicotine per inhalation. When smoking cigarettes, each inhale contains 152–193 micrograms of nicotine. In other words, five inhales of an e-cigarette result in the same amount of ingested nicotine as a single inhale of a cigarette. The average dose received from a single smoked cigarette is 1 mg, or 5–10 inhales depending on the smoking technique. Similar doses have been measured for e-cigarette users. E-cigarette users have also been observed to exhibit equally strong symptoms of nicotine dependence as smokers.

As nicotine replacement products are based on maintaining nicotine dependence, they also contain nicotine. 

Table/infographic: British Medical Journal publication, November 2014: summary of nicotine product doses and their resulting nicotine concentrations in the body