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70 terms

HSER 341 - Test # 8

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Whatr are two major psychoactive metabolites for metabolism of caffeine?
Theophylline and paraxanthine
What is the third major inactive metabolites for metabolism of caffeine
Theobromine
What percentage of the US population consumes caffeine?
80%
What is the most commonly consumed psychoactive drug in the world?
Caffeine
For caffeine - how many minutes for significant absorption?
30-45 minutes
For caffeine - how many minutes until peak plasma levels are reached?
2 hours
For caffeine - how is it distributed throughout the body?
Freely and equally
For caffeine - how much is metabolized in the liver?
90% (10% excreted unchanged)
What is the hepatic enzyme responsible for metabolizing caffeine?
CYP1A2
What can inhibit CYP1A2 and what happens?
Certain SSRI's and caffeine effects are potentiated
What is the T 1/2 of caffeine?
3-5 hours in adults, but extended in infants, pregnant women and elderly
What are the major physiological effects of caffeine?
CNS stimulation; cardiac effects; respiratory changes; diuretic effects
What are some psychological effects of caffeine (at 100-200 mg dose)?
increased alertness and sense of competence; faster clearer flow of thought; increased wakefulness; reduced fatigue
What is adversly affected with caffeine?
delicate motor skills, accurate timing and arithmetic skills
What effects can heavy doses (1000-1500 mg - 1.5g) of caffeine cause?
Agitation, anxiety, tremors, rapid breathing, insomnia
What is the lethal dose of caffeine?
10 grams
How does caffeine effect people with panic disorders?
It can exacerbate or even initiate panic attacks - they do not develop tolerance to this side effect)
What is caffeinism?
Clinical syndrome characterized by both CNS and perpheral symptoms resulting from overuse or overdose of caffeine. Can also be called "caffeine intoxication"
What ar CNS symptoms of caffeine?
Anxiety, agitation, insomnia, mood changes
What are peripheral symptoms of caffeine?
Tachycardia; hypertension; cardiac arrhythmias; gastrointestinal disturbances
What are the impacts of caffeine on the heart?
increased caridiac contractility (workload); increases cardiac output; can increase BP in those prone to such; dilates coronary blood vessels, increasing oxygen delivery
What is the impact of caffeine on the brain?
Constricts cerebral blood vessels, reducing blood flow to brain by about 30% and reducing pressure
What neuromodulator does caffeine resemble?
Caffeine resembles neuromodulator adenosine and has strong affinity for receptors where adenosine binds
What is the impact of caffeine on bronchi?
Relaxes bronchi creating antiasthmatic effect
What is the impact of caffeine on gastric acid?
Increases secretion of gastric acid
What is the impact of caffeine on urine output?
Increases urine output
What is the "drug action" of caffeine?
Caffeine is an antagonist, it does not cause effects, but blocks adenosine from binding
Blocking adenosine disrupts its regulatory activities as a...
Sedative, Depressant, Anticonvulsant
What does adenosine increase activity of?
DA; ACh; Glutamine; NE & GABA (less)
Why does caffeine only have mild behavioral reinforcing properties?
Causes release of DA at prefrontal cortex not the Nucleus Accumbens (reward reinforcement area)
How many pregnant women consume caffeine?
75%
At what level does habituation and tolerance of caffeine develop?
100 mg
What is the typical dependence amount of caffeine?
500 - 600 mg daily X 2 months
What are W/D symptoms of caffeine?
headache; drowsiness; fatigue; negative mood; impaired intellectual and motor performance; difficulty with concentration; caffeine craving
How long to W/D symptoms from caffeine last/
1 - 2 days - will subside in a few days or with readministration of caffeine
What is the primary psychoactive ingredient in tobacco?
Nicotine
What accounts for dependence (addiction) of tobacco?
Nicotine
What is responsible for adverse, long-term cardiovascular effects of tobacco?
nicotine and other compounds in tobacco
What is responsible for adverse, long-term pulmonmary effects of tobacco?
Other compounds in tobacco
What is responsible for adverse, long-term carcinogenic effects of tobacco?
Other compounds in tobacco
What is responsible for much of tobacco's toxicity?
The delivery device (smoking)
Is there any medical use for tobacco?
No (although it makes a good insecticide)
How many chemicals are in tobacco?
4000 (2500 natural & 1500 added)
How is nicotine absorbed?
Through lungs, nasal passages, skin and gastrointestinal tract
How much of available nicotine is inhaled and absorbed into bloodstream?
About 20% (between 0.5 - 2.0mg)
At what levels are blood levels of typical smoker maintained at?
15 ng/ml
How is nicotine distributed?
quickly and thoroughly
What is the hepatic enzyme that metabolized nicotine?
CYP2A6
How much nicotine is metabolized by CYP2A6?
80 - 90%
What is the major metabolite of nicotine and how is it excreted?
Cotinine - excreted by the kidneys
In early stages, what are the physiological effects of nicotine?
causes nausea and vomiting by stimulating vomiting center in brain stem and sensory receptors in stomach (because it is poisonous); tolerance to this effect develops rapidly
What is the impact of nicotine on the hypothalamus?
Stimulates hypothalamus to release antidiuretic hormone that cause fluid retention
What are some of the effects of nicotine on the brain?
reduces weight gain through appetite suppression; increases motor acitvity; increases cognitive functioning, vigilance and rapid information processing; increases sensorimotor performance; increases attention and arousal; increase memory consolidation; increases blood flow to CNS.
What do high doses of nicotine induce?
nervousness and tremors
What is the lethal dose of nicotine?
60 mg (one cigar = 120 mg)
What is the cause of death in nicotine overdose?
asphyxiation from muscle paralysis
What is co-morbid with nicotine addiction?
depression; conduct disorder; ADHD
What is the reinforcing action of nicotine?
indirect activation of midbrain dopamine neurons
What are the effects of nicotine on the body?
Increased heart rate; Increased blood pressure; Increased cardiac contractility; Initiates vasodilation to meet increased oxygen demand; Can precipitate angina or myocardial infarction (heart attack) if blood vessels are atherosclerotic (narrowed and hardened)
With nicotine - what NT is responsible for CNS and peripheral effects?
ACh
With nicotine - what are the peripheral effects from ACh?
increased BP; increased heart rate; release of adrenaline; increased gastrointestinal activity
With nicotine - what are the effects of increased CNS ACh levels?
Cognitive potentiation; memory facilitation; arousal effects
What are W/D symptoms from nicotine?
severe craving for nicotine; irritability; anxiety; anger; difficulty in concentrating; restlessness; impatience; increased appetite; weight gain, insomnia
What is responsible for many of the diseases associated with tobacco use?
Tars
What are the major diseases/problems associated with tobacco use?
Cardiovascular disease; pulmonary disease; cancer; adverse effects on fetus
What percent of pulmonary disease/deaths are tobacco related?
70%
Does nicotine cause cancer?
No - the carcinogenic substances in tars cause cancer
What types of cancer are related to tobacco use?
Lung cancer; mouth, voice box, throat; bladder; pancreatic and uterine/cervical cancer
What percent of all cancer deaths are tobacco related?
30%
What are some effects of tobacco during pregnancy?
adverse effects on developing fetus; increased risk of spontaneous abortion, still birth, SIDS and preterm delivery; growth retardation; low birth rates; increased risk of ADHD, Oppositional Defiant Disorder (ODD), Conduct Disorder and substance abuse later in life