Image source can be found here.
Background (BMJ, 2014):
- Tobacco plants (Nicotiana tabacum and Nicotiana rustica) found mostly in South America, derive an alkaloid called Nicotine, which is main addictive agent in tobacco products.
- Tobacco products can be taken in by smoking cigarettes, chewing tobacco, holding moist snuff in mouth, inhaling dry snuff via nose, inhaling smoke from a waterpipe and inhaling vapour from an electronic cigarette.
- It can be hard to distinguish effects of nicotine compared to other many toxic substances these products contain.
Mechanism of Action (BMJ, 2014):
- Nicotine is a amine that is tertiary including a pyridine and pyrrolidine ring, which joins to nicotinic cholinergic receptors (nAChRs), causing the discharge of dopamine and other neurotransmitter including noradrenaline (norepinephrine), acetylcholine, serotonin, gamma-aminobutyric acid, glutamate and endorphins.
- Constant cigarette smoking decreases brain monoamine oxidase A and B activity, this causes higher amount of monoaminergic neurotransmitters such as dopamine and noradrenaline in synapses, increasing the nicotine effects and giving addiction.
- Reoccurring exposure to nicotine, tolerance starts building with higher number of nAChR binding locations in brain, believed to constitute up-regulation in reaction to nicotine-mediated desensitization of receptors.
Signs and Symptoms of Nicotine, begins at 3:02:(Audiopedia, 2014)
Figure 1 (Schep, 2009):
This table depicts the signs and symptoms of severe nicotinic and nicotinic-like alkaloids exposure.
Treatment (basicfirstaid.ca):
- Wash affected areas of the skin with soap and water for 15 minutes.
- Put some sugar under the tongue.
- Drink Plenty of water or eat a tablespoon of honey.
- Induce vomiting or let the person have activated charcoal to eliminate the poison from the body.
- Mouth-to-mouth resuscitation or CPR in case the persona has difficulty breathing.
- Perform oral suction in case of severe drooling or salivation.
- Oxygen and artificial ventilation when the person has seizures or coma.
- Perform Gastric lavage.
Toxicokinetics (Schep, 2009):
- Nicotine is mainly absorbed through all routes of the exposure including gastrointestinal, dermal, intranasal, and inhalation routes.
- Nicotine has a increased degree of first-pass metabolism with 70-75% being metabolized pre-systemically.
- Nicotine is rapidly and widely distributed throughout most of the body with volume of distribution of 1-3L/kg.
- After intravenous dosing, Nicotine can also distribute to the GI tract, hinting enterohepatic circulation or passive diffusion.
- Nicotine is mainly metabolized by the liver with the making of many metabolites which includes cotinine up to 70-80% of times.
- It is mainly excreted in the urine with terminal half-life averaging 2 hours, and there might be variability depending on the individual which could range from 1-4 hours.
Carcinogenicity: (BMJ, 2014)
Nicotine is not a direct carcinogen, there is no evidence that medicinal nicotine is carcinogenic.
Sources:
Drug and Therapeutics Bulletin. Republished: Nicotine and health. BMJ. 2014 Nov 26;349:2014.7.0264rep. doi: 10.1136/bmj.2014.7.0264rep. PMID: 25428425.
How to treat nicotine poisoning (basicfirstaid.ca)
Schep LJ, Slaughter RJ, Beasley DM. Nicotinic plant poisoning. Clin Toxicol (Phila). 2009 Sep;47(8):771-81. doi: 10.1080/15563650903252186. PMID: 19778187.
“Nicotine Poisoning.” Nicotine Poisoning, Audiopedia, 24 Nov. 2014, www.youtube.com/watch?v=Zbxjz8MsC1g.