M2s3 Nicotine And Caffeine Flashcards
Cost of tobacco to society
-each year 48,000 Canadians die as result of tobacco use
-this number greater than Canadians who die from traffic accidents, alcohol misuse, murder, and suicide combined
-social and economic cost estimates around 16 billion each year
-portion offset by tobacco taxes, reduced healthcare costs to the elderly, reduced pension payments as these people die a premature death
ADME of nicotine
-natural occurring substance found in tobacco and is the ingredient in tobacco products responsible for smoking addiction
- Absorption
-nicotine exists in cigarette smoke in very small particles and when inhaled, droplets are rapidly absorbed
-also absorbed from the gastrointestinal (GI) tract, oral mucosa, and across the skin
-smokers can control the dose of nicotine absorbed by depth of inhalation and by frequency of smoking - Distribution
-distributed throughout body and rapidly gains access to the brain - Metabolism
-rapidly metabolized in the liver - Excretion
-metabolites excreted in the urine. The half-life of nicotine in the body is about 2 hours
Mechanism of action of nicotine
- refer to goodnotes for photo
-stimulates nicotinic receptors at synapses, similar to acetylcholine (ACh)
-activation of nicotinic receptors increases psychomotor activity, cognitive function, attention and memory
-in large doses, nicotine can cause agitation, tremors and seizures
-effects in the CHS are mediated at least in part, by nicotinic receptor-mediated release of the CHS neurotransmitters dopamine and serotonin
Therapeutic use of Nicotine
-only therapeutic use of nicotine is in smoking cessation programs where nicotine is administered in form of chewing gum, transdermal patches or buccal spray
-this approach attempts to maintain the blood nicotine levels and satisfy the craving for a cigarette, allowing for tampering of the nicotine dose
Smoking in 1960s
-1940s to 70s tobacco products increased as it was considered cool
-over past 4 decades, percentage of adult population that smokes has declined to where only about 15% of males and females over the age of 12 smoked in 2019
-but fact 15% of population still smokes is high considering the link between smoking and health problems like cancer, cardiovascular diseases and respiratory diseases
Commercial
-talks about follow doctor and they have cigarette when so busy
-“doctors in all branches of medicine and parts” they all have camels
-‘camels agree with throat and good tasting”
Short-term effects of smoking
In regular smoker, short-term effects of nicotine:
-mild euphoria
-enhanced arousal
-increased ability to concentrate
-sense of relaxation
-may cause small in heart rate and blood pressure and may suppress appetite
In non-regular smoker
-few puffs of cigarette may result in dizziness, headache, nausea, vomiting and abdominal cramps
-smoke may trigger coughing and gagging
-these symptoms disappear in the chronic smoker
Long-term effects of smoking
-tobacco contains approximately 4000 compounds, including nicotine, carbon monoxide, carcinogenic aromatic hydrocarbons, tars, and many other productions of combustion
-in long-term respiratory and carcinogenic effects of smoking related to these products of combustion and not to nicotine itself
Cardiovascular disease
-smoker has higher risk of death due to cardiac causes
-while long-term respiratory and carcinogenic effects of smoking are related to these products of combustion and not to nicotine, nicotine has been linked to cardiovascular disease
-carbon monoxide reduces capacity of red blood cells to carry oxygen
-both nicotine and carbon monoxide increase the incidence of atherosclerosis (narrowing and hardening of arteries due to buildup of plaques) and formation of thrombi (blood clots)
Lung disease
-one type is smoker’s syndrome characterized by difficulty in breathing, wheezing, chest pain, congested lungs, and increased lung infections
-increased risk of emphysema and other forms of chronic obstructive lung disease
Cancer
-30% of all cancers are estimated to be caused by cigarette smoke
-known to increase risk of cancer of lungs, oral cavity and throat, bladder and uterus
Other effects of smoking (children, during pregnancy)
-exposure to passive smoke (second hand smoke) is associated with increased risk of cardiovascular disease and cancer. In children, passive smoke increases risk of bronchitis, pneumonia, asthma and sudden death syndrome (SIDS)
Smoking during pregnancy
-has adverse effects on developing fetus
-2 to 3 fold increase exists in the incidence of the fetus being small for gestational age or being born preterm
-effect appears to reverse if the pregnant person stops smoking early in pregnancy
-exposure to passive tobacco smoke during pregnancy also increases the chance of a low birth weight neonate
-mechanism of this effect due to decreased oxygen delivery to fetus
Nicotine: potential for misuse and SUD
-Health Canada and royal society of Canada state tobacco products meet all requirements of addictive substances
-attempts to cessation of smoking often fail as craving of nicotine is so great
-smoking cessation programs usually involve counselling and pharmacological support (e.g. nicotine replacement programs)
Tolerance
-does not appear to occur to any great extent
-most smokers smoke to keep nicotine blood levels at certain range (30 to 49 nanograms/millilitre)
-number of cigarettes smoked each day is the number needed to keep the nicotine at this level
Withdrawal
-number of symptoms including irritability, restlessness, anxiety, insomnia, fatigue and inability to concentrate
-upon awakening in the morning, the smoker is in a state of nicotine withdrawal
Addition
-occur and manifest as an extreme urge to smoke
Pharmacology of caffeine
-found in significant concentrations in tea, coffee, chocolate and cola drinks
-found in over-the-counter stimulants, analgesics and diuretics (substances that increase urine production and the excretion of water from the body through the kidneys)
-average coffee cup contains about 100 mg of caffeine, while energy drinks can contain over 300 mg of caffeine
-lethal dose of caffeine does exist, and is equal to about 10 g of caffeine (I.e., about 57 cups of medium strength coffee)
ADME of caffeine
-most widely and regularly used drug in the world
-predominantly affects CNS and the cardiovascular system as a stimulant
- Absorption
-taken orally, caffeine is rapidly and completely absorbed
-blood levels of caffeine are significant at 30 minutes, and then peak 2 hours after ingestion - Distribution
-caffeine distributes to all parts of the body and freely crosses into the brain and placenta - Metabolism
-genetics determine rate and which we metabolize and excrete caffeine
-there are rapid metabolizes and slow metabolizes
-may explain why drinking coffee with dinner keeps some individuals awake, but not others - Elimination
-half-life of caffeine varies among individuals from 2.5 to 10 hours
Mechanism of action of caffeine
- refer to goodnotes for image
-100-250 mg of caffeine (the amount of caffeine in one to two cups of strong coffee) increases mental performance and motor activity while decreasing drowsiness and fatigue
Without caffeine:
In brain, activation of receptors termed adenosine receptors stimulates GABAergic neurons that then inhabit dopamine release
With caffeine:
The actions of caffeine are exerted by competitively blocking adenosine receptors in the brain
When caffeine blocks these adenosine receptors, the neurons are released from the adenosine inhibition, causing an increase in dopamine release
-overall effect is stimulation of the CNS
Short-term effects of caffeine
CNS
-produce mild mood elevation and reduce fatigue
-small increase in performance may exist, but this has not been conclusively demonstrated
-flow-of-thought may be clearer and more rapid
-when taken by abstainers, caffeine produces nervousness and can interfere with sleep
-high doses will produce irritability, nervousness, rambling flow of thoughts and speech, and psychomotor agitation
Cardiovascular
-caffeine produces constriction of cerebral blood vessels (useful during a headache), increases peripheral blood flow, and stimulates cardiac muscle (I.e., heart rate is increased)
-with high dose one will Experince a rapid and irregular heartbeat
Respiration
-mild stimulation of respiratory rate and a relaxation of bronchial smooth muscle occurs with caffeine
-clinically, caffeine is used to stimulate breathing in preterm newborns, as it helps their immature brains and lungs remember to breathe
Long-term effects of caffeine
-long-term caffeine use affects multiple body systems as well
-long-term effects of caffeine, which are the results of excessive use over a long period of time are:
-restlessness
-nervousness
-insomnia
-increased urinary output
-gastric upset
-rambling speech and thought
*no definite link between caffeine composition and disease states exist, although not all experts agree
Effects of caffeine in special circumstances
caffeine and smoking
-cigarette smoke increases the metabolism of caffeine therefore in smokers the duration of caffeine is shortened
-when a person quits smoking, the metabolism of caffeine returns to normal, thus smoking cessation should prompt decreased caffeine intake
Caffeine and pregnancy
-not teratogenic, in that consumption of caffeine not associated with fetal abnormalities
-however, large doses of caffeine (i.e., 12 cups of coffee per day) during pregnancy increases the risk of stillbirth from 4/1000 to 12/1000, slightly decreases fetal growth rate, and slightly increases the chance of miscarriage. Modest doses (I.e., 3 cups of coffee per day) were without any measurable effects of the fetus
-note that metabolism of caffeine is slower in pregnant people, extending the duration of action of caffeine
-in fact, caffeine remains in body 2 times long we in the second trimester and 3 times longer in third trimester so pregnant people often decrease their intake of caffeine to avoid feeling irritable or unwell
