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Test 3 - Drugs and Behavior

Terms in this set (57)

Absorption:
- some alcohol is absorbed from the stomach + the small intestine is responsible for most absorption
- empty stomach rate of absorption depends primarily on concentration of alcohol
- the carbon dioxide acts to move everything rapidly through the stomach to the small intestine
- because of emptying of stomach + rapid absorption of alcohol in the intestine that champagne has faster onset of action than non-carbonated wine

Dilution:
- relationship between blood alcohol content (BAC) and alcohol intake
- when taken into the body alcohol is distributed through the body fluids like the blood + alcohol does not distribute much into fatty tissues
- table 9.2 demonstrates relationships between alcohol intake, BAC, and body weight for hypothetical average females and males
- the average female has higher proportion of body fat and for a given weight has less volume in which to distribute the alcohol
- compared with men, women absorb a greater proportion of the alcohol they drink
- some metabolism of alcohol occurs in the stomach where the enzyme alcohol dehydrogenase is present
- because this stomach enzyme is more active in men than in women then women are more susceptible to the effects of alcohol

Metabolism:
- once absorbed then alcohol remains in the bloodstream and other body fluids until it is metabolized and more than 90% of this metabolism occurs in the liver
- primary metabolic system:
- enzyme alcohol dehydrogenase converts alcohol to acetaldehyde
- acetaldehyde is converted rapidly by aldehyde dehydrogenase to acetic acid
- with most drugs a constant proportion of the drug is removed in a given amount of time + with a high blood level the amount metabolized is high
- with alcohol the amount that can be metabolized is around 0.25 - 0.3 ounces per house regardless of the BAC
- major factor in determining the rate of alcohol metabolism is the activity of the enzyme alcohol dehydrogenase


blood alcohol concentration (also called blood alcohol level):
- a measure of the concentration of alcohol in blood, expressed in grams per 100 ml (percentage)
- fatty acids are usual fuel for the liver + when present alcohol has higher priority and is used as fuel instead
- as result fatty acids (lipids) accumulate in the liver + stored as small droplets in liver cells
- condition known as alcohol-related fatty liver (for most drinkers not a serious problem)
- alcohol input ceases - liver uses stored fatty acids for energy
- droplets may increase in size until they rupture cell membrane + cause death of the liver cells
- before liver cells die + fatty liver is completely reversible + minor medical concern

Alcohol Hepatitis:
- alcohol hepatitis is a serious disease and includes both inflammation and impairment of liver function
- this occurs in areas of the liver where cells are dead / dying
- it is not known if increasingly fatty liver leads to alcoholic hepatitis

Cirrhosis:
- liver disease everyone knows related to high and prolonged levels of alcohol consumption
- takes about 10 years of steady drinking or equivalent of a pint or more of whiskey a day
- not all cirrhosis is alcohol-related but high percentage is
- in cirrhosis - liver cells are replaced by fibrous tissue (collagen) which changes the structure of the liver
- these changes decrease blood flow + along with loss of cells (results in decreased ability of the liver to function)
- when liver does not function properly then fluid accumulates in the body, jaundice develops, and other infections / cancers have better opportunity to establish themselves in the liver
- cirrhosis not reversible but stopping intake of alcohol will slow its development / decrease serious medical effects
- cirrhosis is an irreversible, frequently deadly liver disorder that is associated with heavy alcohol use
Withdrawal Syndrome:
The physical dependence associated with prolonged heavy use of alcohol is reversed when alcohol intake is stopped

Detoxification:
- recommended that initial period of detoxification (allowing body to rid itself of the alcohol) be carried out in an inpatient medical setting
- Progression of withdrawal described in the following way:
- Stage 1: tremors, excessively rapid heart beat, hypertension, heavy sweating, loss of appetite and insomnia
- Stage 2: hallucinations such as auditory, visual, tactile, or a combination of these, and rarely olefactory signs
- Stage 3: delusions, disorientation, delirium, sometimes intermittent and usually followed by amnesia
- Stage 4: seizure activity

- medical treatment usually sought in stage 1 or 2 (rapid intervention with sedative drug sych as diazepam will prevent stage 3 or 4 from occurring)

Delirium tremens:
- term used to refer to severe cases including at least stage 3

Fetal alcohol effect:
- individual developmental abnormalities associated with mother's alcohol use during pregnancy

Detoxification:
- an early treatment stage, in which the body eliminates the alcohol or other substances

Delirium tremens:
- an alcohol withdrawal symptom that includes hallucinations and tremors

- Optimal treatment of patients during the early stages involves the administration of a benzodiazepine such as chlordiazepoxide or diazepam
- because of high degree of cross dependence between alcohol and chlordiazepoxide then one drug can be substituted for the other and withdrawal continued at safer rate
- withdrawal symptoms can last for up to several weeks like unstable blood pressure, irregular breathing, anxiety, panic attacks, insomnia, and depression
- phenomena referred to as a protracted withdrawal syndrome + can trigger intense cravings for alcohol
- early 1970s cigarette smokers began to look for alternatives that would reduce the risk of lung cancer
- pipe and cigar smoking have brief increase followed by long period of decline
- sales of smokeless tobacco products such as different types of chewing tobacco - began to increase

Oral Smokeless tobacco:
- most common type of oral smokeless tobacco in the United States is moist snuff which is sold in a can
- moist snuff is not snuffed into the nose in the traditional manner + small pinch dripped out of the can and placed beside the gum / behind the lower lip
- moist snuff has traditional popularity base in rural west
- moist snuff continue to show sales gains through the 1980s + federal exise tax was imposed
- with all forms oral smokeless tobacco + nicotine is absorbed through the mucous membranes of the mouth + into the bloodstream
- users achieve blood nicotine levels comparable to those of smokers


Advantages of smokeless tobacco:
- smokeless tobacco unlikely to cause lung cancer
- smokeless tobacco is less expensive than cigarettes with an average user spending only a few dollars a week
- use of chewing tobacco never died out completely in rural areas + resurgence was strongest there

Health Hazards:
- chewing tobacco might not be as unhealthy as smoking it
- smokeless tobacco not without its hazards
- concerns are increased risk of cancer of the mouth, pharynx, and esophagus
- snuff + chewing tobacco contain potent carcinogens including high levels of tobacco-specific nitrosamines
- many users experience tissue changes in the mouth with leukoplakia
- leukoplakia = a whitening, thickening and hardening of the tissue + considered to be a precancerous lesion (lesion is a tissue change that can develop into cancer)
- the irritation of the gums can cause them to become inflamed or recede + expose the teeth to disease
- enamel of the teeth can be worn down by abrasive action of the tobacco
- Dentists becoming more aware of the destructive effects of oral tobacco

Smokeless tobacco: A term used for chewing tobacco during the 1980s

Moist snuff: Finely chopped tobacco, held in mouth rather than snuffed into the nose

Quid = a piece of chewing tobacco

Nitrosamines = a type of chemical that is carcinogenic ; several found in tobacco

Leukoplakia: a whitening and thickening of the mucous tissue in the mouth + considered to be a precancerous tissue change

- 1986 The Health Consequences of Using Smokeless Tobacco:
- concerns about these oral diseases led to the surgeon general's office to sponsor a conference and produce 1986 report
- this report went into some depth in reviewing epidemiological, experimental, and clinical data
- smoking can cause cancer, number of noncancerous oral conditions, and can lead to nicotine addiction and dependence
- nicotine + hydrogen cyanide + carbon monoxide in a smoking mother's blood also reach the developing fetus and have significant negative consequences there
- on average infants born to smokers are about half a pound lighter than infants born to non-smokers
- there is a dose-response relationship + the more the mother smokes during pregnancy then the greater the reduction in birth weight
- smoking shortens the gestation period by an average of 2 days and when gestation length is accounted for the smokers still have smaller infants
- the infants of smokers are normally proportioned but are smaller and shorter than the infants of nonsmokers + and have smaller head circumference
- besides the developmental effects evident at birth + several studies indicate small but consistent differences in body size, neurological problems, reading and mathematical skills and hyperactivity at various ages
- smoking during pregnancy can have long-lasting effects on both the intellectual and physical development of the child

- the increased perinatal (close to the time of birth) + smoking attributable mortality associated with sudden infant death syndrome (SIDS), low birth weight, and respiratory difficulties adds up to about 10,000 infant deaths per year in the United States

- spontaneous abortion (miscarriage) has also been studied many times in relation to smoking and with consistent results
- smokers have more spontaneous abortions than nonsmokers
- congenital malformations + evidence for a relationship to maternal smoking is not clear
- effect of nicotine on areas outside the central nervous system has been studied extensively
- nicotine mimics acetylcholine by acting at several nicotinic subtypes of cholinergic receptor site
- nicotine is not rapidly deactivated + continued occupation of the receptor prevents incoming impulses from having an effect (blocks the transmission of information at the synapse)
- nicotine first stimulates and then blocks the receptor + these effects at cholinergic synapses are responsible for some of nicotine's effects

- nicotine causes a release of adrenaline from the adrenal glands and other sympathetic sites + has a sympathomimetic action
- stimulates and then blocks some sensory receptors found in large arteries and the thermal pain receptors found in the skin and tongue

Toxic effects of nicotine:
- in acute poisoning + nicotine causes tremors which develop into convulsions which are terminated frequently by death
- the cause of death is suffocation resulting from paralysis of the muscles used in respiration
- this paralysis stems from the blocking effect of nicotine on the cholinergic system that normally activates the muscles

- with lower doses respiration rate increases because the nicotine stimulates oxygen-need receptors in the carotid artery
- at these lower doses of 6-8 mg there is a considerable effect on the cardiovascular system as a result on the release of adrenaline
- such release leads to an increase in coronary blood flow + along with vasoconstriction in the skin + increased heart rate + increased blood pressure
- increased heart rate and blood pressure raise the oxygen need of the heart but not the oxygen supply

- nicotine increases platelet adhesiveness which increases the tendency to clot
- within the central nervous system nicotine acts at the level of the cortex to increase the frequency of the electrical activity
- shift the EEG toward an arousal pattern

- inhaling while smoking cigarettes
Xanthines:
- xanthines are the oldest stimulants known
- three xanthines are of primary importance are caffeine + theophylline + theobromine
= these three chemicas are methylated xanthines and are closely related to alkaloids (different because slightly water soluble)

- these three xanthines have similar effects on the body
- caffeine has the greatest effect + least potent
- theophylline is the most potent

Time Course:
- in humans the absorption of caffeine is rapid after oral intake + peak blood levels are reached 30 minutes after ingestion
- maximal central nervous system effects are not reached for about 2 hours + onset of effects can begin half hour after intake
- half-life in humans = 3 hours (no more than 10% is excreted unchanged)

- cross tolerance exists among the methylated xanthines + loss of tolerance can take more than two months of abstinence
- tolerance is low grade and by increasing dose 2 to 4 times an effect can be obtained even in the tolerant individual
- there is less tolerance to the CNS stimulation effect of caffeine than to most other effects
- direct action on the kidneys to increase urine output + the increase of salivary flow show tolerance

Dependence on Caffeine:
- dependence on caffeine is real
- people who are not coffee drinkers / have been drinking only decaffeinated coffee often report unpleasant effects (nervousness / anxiety) after being given caffeinated coffee
- those who regularly consume caffeine report mostly pleasant mood states after drinking caffeine

Caffeinism:

- caffeinism or excessive use of caffeine can cause a variety of unpleasant symptoms
- nervous, irritability, tremulousness, muscle twitching, insomnia, flushed appearence, elevated temperature can result from excessive caffeine use
- there can be palpitations + heart arrhythmias + gastrointestinal disturbances


- the most reliable withdrawal syndrome is a headache which occurs on average from 18-19 hours after the most caffeine intake
- other symptoms include increased fatigue and decreased sense of vigor
- withdrawal symptoms strongest during first 2 days of withdrawal then decline over next 5-6 days

- Xanthines: class of chemicals to which caffeine belongs