What is Nicotine?
They have naturally produced alkaloids in the nightshade family of plants (most predominantly in tobacco and Dubois, hopwoodii) and are widely used recreationally as a stimulant and anxiolytic. As a pharmaceutical drug, it is used for smoking cessation to relieve withdrawal symptoms. Nicotine acts as a receptor agonist at most nicotinic acetylcholine receptors except at two nicotinic receptor subunits where it acts as a receptor antagonist. It constitutes approximately 0.6–3.0% of the dry weight of tobacco. It functions as an anti-herbivore chemical; consequently, nicotine was widely used as an insecticide in the past, and neonicotinoids, such as ‘imidacloprid,’ are some of the most effective and widely used insecticides.
A handful of animal research suggests that monoamine oxidase inhibitors present in tobacco smoke may enhance nicotine's addictive properties. Tobacco with reduced nicotine (denicotinized tobacco) acutely reduces nicotine withdrawal, raises striatal dopamine which is also investigated as add-on therapy to standard therapy to quit smoking. An average cigarette yields about 2 mg of absorbed nicotine. The estimated lower dose limit for fatal outcomes is 500–1,000 mg of ingested nicotine for an adult (6.5–13 kg). Nicotine addiction involves drug-reinforced behavior, compulsive use, and relapse following abstinence. Nicotine dependence involves tolerance, sensitization, physical dependence, and psychological dependence. Nicotine dependence causes distress. Nicotine withdrawal symptoms include depressed mood, stress, anxiety, irritability, difficulty concentrating, and sleep disturbances. Mild nicotine withdrawal symptoms are measurable in unrestricted smokers, who experience normal moods only as their blood nicotine levels peak, with each cigarette. On quitting, withdrawal symptoms worsen sharply, and then gradually improve to a normal state.
It is as effective as medications in helping people quit smoking for at least 6 months. All forms of nicotine replacement therapy, including nicotine gum, patches, nasal spray, inhalers, and lozenges, have similar success rates in terms of helping people stop smoking. However, the likelihood that someone will stick to a certain treatment varies, with compliance being the highest with nicotine patches, followed by nicotine gum, inhalers, and nasal sprays. Using a few different nicotine replacement methods in combination may improve success rates in stopping tobacco use. Nicotine replacement products are most beneficial for heavy smokers who smoke more than 15 cigarettes per day. There are not enough studies to show whether NRT helps those who smoke fewer than 10 cigarettes per day.
Nicotine has a similar configuration, commonly known as ‘Tobacco’
It has derived from a chief commercial crop known as ‘Nicotiana.’ Tobacco leaves are mainly used for smoking in cigarettes and cigars, as well as pipes and shishas. They can also be consumed as snuff, chewing tobacco, dipping tobacco. Tobacco contains the highly addictive stimulant alkaloid nicotine as well as alkaloids. Gradually it becomes a cause or risk factor for many deadly diseases, especially those affecting the heart, liver, and lungs, as well as many cancers. In 2008, the World Health Organization named tobacco use as the world's single greatest preventable cause of death.
The uses of tobacco, primarily in cigars, became associated with masculinity and power. Today, tobacco use is often stigmatized; this has spawned quitting associations and antismoking campaigns. Bhutan is the only country in the world where tobacco sales are illegal. Due to its propensity for causing detumescence and erectile dysfunction, some studies have described tobacco as an aphrodisiacal substance.
Overdose and its unfavorable effects: - In 2017 WHO released a study on the environmental effects of tobacco.
It has been observed that a person would overdose on nicotine through smoking alone. Sufficiently high doses, it is associated with nicotine poisoning, while common in children in whom poisonous and lethal levels occur at lower doses per kilogram of body weight which rarely results in significant morbidity or death. The estimated lower dose limit for fatal outcomes is 500–1,000 mg of ingested nicotine for an adult 6.5mg. The initial symptoms of a nicotine overdose typically include nausea, vomiting, diarrhea, hypersalivation, abdominal pain, tachycardia (rapid heart rate), hypertension (high blood pressure), tachypnea (rapid breathing), headache, dizziness, pallor (pale skin), auditory or visual disturbances, and perspiration, followed shortly after by marked bradycardia (slow heart rate), bradypnea (slow breathing), and hypotension (low blood pressure). Respiratory stimulation (i.e., tachypnea) is one of the primary signs of nicotine poisoning.
At sufficiently high doses, somnolence (sleepiness or drowsiness), confusion, syncope (loss of consciousness from fainting), shortness of breath, marked weakness, seizures, and coma may occur. People who harvest or cultivate tobacco may experience Green Tobacco Sickness (GTS), a type of nicotine poisoning caused by dermal exposure to wet tobacco leaves. This occurs most commonly in young, inexperienced tobacco harvesters who do not consume tobacco.
Though smoking is associated with a decreased risk of Parkinson's Disease; however, it is unknown whether this is due to people with healthier brain dopaminergic reward centers (the area of the brain affected by Parkinson's) being more likely to enjoy smoking and thus pick up the habit, nicotine directly acting as a neuroprotective agent, or other compounds in cigarette smoke acting as neuroprotective agents. However, several in vitro studies have investigated the potential effects of nicotine on a range of oral cells. A recent systematic review concluded that nicotine was unlikely to be cytotoxic to oral cells in vitro in most physiological conditions but further research is needed. Understanding the potential role of nicotine in oral health has become increasingly important given the recent introduction of novel nicotine products and their potential role in helping smokers quit.