Introduction

Nicotine is commonly known for its highly addictive properties, but most of the time, its large potential for poisoning is overlooked. Nicotine is widely found in products such as tobacco, e-cigarettes, cigars, and nicotine gums. If ingested in large quantities, it can lead to serious poisoning incidents, which would need immediate medical attention.¹  

Nicotine can be ingested through the mouth directly, inhaled through the nose, or absorbed from the skin or eyes. Excessive nicotine exposure can impose serious health risks that are discussed further below in the article. 

Understanding nicotine 

Nicotine is a toxic alkaloid that is only found in tobacco plants. According to multiple scientifically supported studies, the median lethal dose of nicotine to cause death is 30-60 mg per average human.³ In comparison to nicotine, cocaine has a median lethal dose much higher than that of nicotine. 

Mechanism of action 

When a person smokes nicotine, it swiftly reaches the brain, easily crossing the blood-brain barrier (BBB), where it turns on tiny receptors called nicotinic acetylcholine receptors (nAChRs). Once these receptors are turned on, they release dopamine, the hormone that gives a feeling of happiness to the body. Over time, the body starts getting used to the constant release of the feel-good hormone and craves nicotine more. Without nicotine, the body misses the dopamine boost and starts feeling anxious, stressed out, and irritable. This is the stage of addiction, and where one experiences withdrawal symptoms. To alleviate these negative emotions, someone would reach out for more cigarettes.

Absorption - how nicotine gets inside the body 

There are various routes through which nicotine can enter the bloodstream and later reach the brain.. Nicotine comes in different packaging. Some of which include:

1. Smoking/Vaping: it is the fastest route for nicotine to reach the brain and take effect, as it passes through the lungs, enters the bloodstream, and reaches the brain within a few seconds²
2. Gums/Patches: these take a slow onset of action and produce fewer cravings in comparison to vapes or cigarettes

Nicotine toxicity: how it happens  

The number of nicotine-induced toxicities and addictions has increased drastically ever since the marketing of new e-cigarettes and other new nicotine-containing products like smokeless tobacco. 

It is an old myth that a 60 mg dose can cause death in a human being, but in current times, this dose is considered too low. Regardless of the chances of death being scarce, the chances of toxicity are still prevalent. The actual risk of death from nicotine overdose is from around 0.5 -1g of ingestion.³

Cumulative risk - chain smoking risk 

Chain smoking, which involves lighting one cigarette right after another, results in constant nicotine consumption, which exacerbates dependence and produces nausea, dizziness, and a fast heartbeat. Additionally, it increases levels of carbon monoxide and toxins, which boosts the risk of cancer, lung damage, and heart disease. This tendency makes it more difficult to overcome nicotine addiction over time. 

Who is more likely to get nicotine sick? 

Children and adolescents

The low body weight of children and adolescents causes nausea, vomiting, disorientation, and severe poisoning when they consume a single cigarette or a cigarette butt. 

When a toddler accidentally takes cigarettes or e-liquids, it can lead to nicotine poisoning. 

Non-smokers and new smokers

People who lack tolerance are extremely vulnerable to the effects of nicotine. Inexperienced or first-time smokers sometimes suffer from "green tobacco sickness," which includes sweating, lightheadedness, nausea, and a fast heartbeat after just a few puffs or cigarettes.

Double-dippers

Higher total nicotine intake results from combining cigarette smoking, vaping, chewing tobacco, or nicotine replacement (gum or patches).In particular, when taken in close succession, this raises the risk of overdose symptoms.

Symptoms of nicotine poisoning

Mild to moderate symptoms 

Signs and symptoms to look out for:

1. Nausea and Vomiting⁴
2. Dizziness 
3. Tachycardia or Palpitations
4. Gastrointestinal disturbances, i.e., Abdominal pain, Diarrhoea, Constipation
5. Excessive Sweat

Severe nicotine poisoning symptoms

1. Neurological: Confusion, seizures, muscle weakness, or paralysis⁴
2. Cardiovascular: Rapid or irregular heartbeat, dangerously low or high blood pressure
3. Respiratory: Slow, laboured, or difficulty breathing
4. Gastrointestinal: Severe nausea, vomiting, and abdominal cramps
5. Other critical signs: Pale, clammy skin; loss of consciousness or coma

Smoking and bodyweight

Obesity and smoking are the two main global causes of morbidity and death. Significant health risks result from smoking and being overweight. According to the Framingham research, obese smokers had a 13-year lower life expectancy than nonsmokers of normal weight.⁷

Because of the metabolic effects of nicotine, smoking is generally linked to lower body weight than that of nonsmokers. Nicotine inhibits hunger, which results in a decrease in caloric intake, and raises energy expenditure by increasing the resting metabolic rate. Adult smokers are therefore less likely to be overweight or obese and usually weigh 4–5 kg less than nonsmokers.⁸

Smokers also tend to gain weight after quitting—an average of 5–6 kg—with the majority of weight regained in the first 6 months of abstinence. Additionally, while smokers generally have lower body weight, those who smoke heavily may actually have higher BMI and more abdominal fat than lighter smokers or nonsmokers, possibly due to clustering of other unhealthy lifestyle factors.⁹

Diagnosis and treatment

Diagnosis 

The physician will rule out the chances of nicotine overdose by:

1. Physical examination: look for signs and symptoms related to poisoning, i.e., nausea, vomiting, gastrointestinal disturbances, palpitations, seizures
2. Questioning: the physician will ask the affected person or close kin about any recent nicotine exposure in the form of vaping, e-liquid ingestion
3. Lab Tests: blood/urine test for detecting nicotine or its active metabolite, i.e,. cotinine

Treatment

Activated charcoal is given to absorb nicotine from the stomach and prevent any further complications.

Hospital care may include:

• IV Fluids
• Oxygen therapy
• Benzodiazepines as an anti-seizure medication
• Atropine for palpitations 

Things to keep in mind

• Vomiting should not be induced, as it can further worsen the lung condition
• Stop nicotine exposure immediately 
• Hydration is important

Prognosis: what’s the outlook?

The prognosis is generally good. The outcome largely depends on how quickly treatment is administered and the severity of nicotine exposure. 

Prevention and public health implications  

Preventive strategies for extensive nicotine exposure leading to poisoning include:

• Public awareness campaigns: counselling of addicts, education of parents and youngsters regarding the dangers of nicotine poisoning, such as nicotine pouches⁶ 
• Warning labels: to keep out of the range of children
• Healthcare workers' training programs: Clinical training programs should be implemented to educate healthcare workers on the proper diagnosis and management of nicotine poisoning

Summary

Nicotine overdose and poisoning, a condition in which the body absorbs more nicotine than it can handle, can result from excessive cigarette smoking. Nicotine originates from an alkaloid found in tobacco plants and can exert toxic effects on the body when consumed in large amounts. Nicotine poisoning may lead to symptoms such as nausea, vomiting, gastrointestinal disturbances, seizures, and palpitations, often requiring emergency medical care.

The incidence of nicotine poisoning is higher among individuals who are chain smokers, dual users (e.g., using patches and smoking simultaneously), heavy vapers, or those who consume nicotine e-liquids.

Although supportive care is the primary means of treatment, medical treatment for nicotine overdose typically involves the administration of activated charcoal to limit further absorption, but inducing vomiting is not recommended. Diagnosis can be confirmed by detecting cotinine, an active metabolite of nicotine, in the urine. When treated promptly, recovery is common; nevertheless, serious poisoning necessitates immediate medical assistance.