Module 2 - Drug misuse and addiction Flashcards
What is SUD?
- social impairements
- risky use
- impaired control
- withdrawal
- tolerance
Addiction
the impaired control associated with SUD manifests as emotional and mental preoccupation with the effects of the drug and by persistent craving for the drug
addiction = a state in which stopping or abruptly reducing the dose of a given drug produces non-physical symptoms
Dopamine hypothesis and addiction
2 components:
- effects on the reward systems: commonly misused drug increases dopamine in the reward system of the brain
- dopamine increase: dopaminergic systems are also responsible for natural rewards
Characteristics of addictive drugs
- increase dopamine
- produce novelty
- reduce anxiety
Drug withdrawal
symptoms are usually the opposite of the effects of the drug
Drug tolerance
drug tolerance is expressed as a shortened duration of action and a decreased magnitude to the effect
tolerance does not develop to all drugs, not to all aspects of a drugs action
drug tolerance is reversible upon drug discontinuation
Cross tolerance
can occur between pharmacologically similar drugs
defined as the resistance or tolerance to one drug because of the resistance to tolerance to a pharmacologically similar drug
* displayed in the dose-response curve
Factors influencing SUD
- genetic factors - can predispose an individual to SUD
- pre-existing disorders - mental illness are at higher risk of SUD
- environmental factors - family dynamics, trauma, social groups
- developmental factors - adolescence and early adulthood
Stigma of SUD
stigmatized = judged by others without knowing anything about the individual
Harm reduction
seeks to reduce/prevent the negative consequences of substance use and improve health without judgment, coercion, or discrimination, and without necessarily requiring the person to stop using the substance
- health harms
- goal is to decrease morbidity and mortality - societal harms
- goal is to decrease lost productivity, apprehension of children, criminal activity
Misuse of substances
misuse = using the drug in ways or amounts other than what was prescribed, or against social norms
Potential for misuse
5 factors:
1. nature of the drug
2. route of administration
3. amount frequency of use
4. availability
5. inherent harmfulness
Amphetamines
controlled substance (restricted for certain medical conditions: narcolepsy)
the amphetamines drug class includes dextroamphetamine and methamphetamine
compounds are:
1. ritalin
2. ecstasy
Amphetamines: CNS effects
- a decreased threshold for transmitting sensory input to the cerebral cortex, leading to CNS excitation → can cause overstimulation, restlessness, dizziness, mild confusion, tremor, and in rare instances panic and psychosis, especially with higher doses
- a feeling of euphoria and reward
- temperature-regulated and feeding centre modifications leading to appetite suppression
- an increase in aggressive behaviour and mood swings
Other effects of amphetamines
Short term use:
- chest pain or heart attack
- cardiovascular collapse
- increased respiratory rate
- overdose may result in a seizure, high fever, or stroke
Long term use:
- chronic sleeping problems
- poor appetite
- anxiety, repetitive behaviour, psychoses, aggressive behaviour
- elevated blood pressure and abnormal cardiac rhythm
Concurrent use:
- use of other drugs in an attempt to antagonize various toxic effects of the amphetamines
- example: people who experience sleeping problems may seek out a CNS depressant to help them sleep
- this can lead to additional issues such a drug-drug interactions, misusing of additional drugs, and potentially SUD
Therapeutic use of Amphetamines
- narcolepsy
- chronic sleep disorder
- ADHD
- drug therapy can calm hyperactivity and improve attention and control
Amphetamines potential misuse
- produce powerful euphoria
- water-soluble salt forms of the drug allow for large doses that are readily injectable, resulting in rapid and intense response
- inherent harmfulness of amphetamines is due to their long-term toxicities, including cardiovascular effects and drug-induced psychoses
Amphetamines potential SUD
tolerance: occurs, develops to the euphoria and mood-elevating effects but not to therapeutic effects
withdrawal: occurs, cessation of use results in mood depression that may be profound, prolonged sleep, huge appetite, lack of energy, and fatigue
addiction: occurs, will crave the drugs effects so intensely that if it is not available they will experience panic
Cocaine
CNS stimulant
classified as a narcotic
cocaine has a shorter duration of actions, which is usually less than an hour
cocaine is commonly sniffed or smoked
Mechanism of action of cocaine
- Reuptake Inhibition:
- inhibits the active re-uptake of primarily dopamine and serotonin into the presynaptic neuron
- postsynaptic neuron activation
- increases the concentration of these neurotransmitters in the synaptic cleft, and in turn, increases the activation of the receptors of the post-synaptic neurons
Therapeutic use of cocaine
the only legitimate use of cocaine is as a local anesthetic for the mouth and throat
Long term effects of cocaine
- toxic psychosis including paranoia
- hallucinations or sensations of insects crawling under the skin
- impaired sexual function
- permanent brain damage and impairment of neuronal function may occur
- high blood pressure and an irregular heart rhythm
- changes to the nasal mucosa and the drug is sniffed
Long term effects of cocaine
- toxic psychosis including paranoia
- hallucinations or sensations of insects crawling under the skin
- impaired sexual function
- permanent brain damage and impairment of neuronal function may occur
- high blood pressure and an irregular heart rhythm
- changes to the nasal mucosa and the drug is sniffed
Cocaine potential for misuse
- due to powerful euphoria, which can be reached rapidly by injecting the drug or smoking the freebase
- freebase = a purified form of cocaine that has a low melting point making it easier to smoke
- the inherent harmfulness of cocaine involves the fact that those who take the drug will experience physical or psychological deficits
- these events do not appear to deter misuse
Cocaine potential for SUD
Tolerance: develops towards the mood-elevating effect of cocaine but not the drug-induced psychotic effect
Withdrawal: occurs, similar to amphetamines
Addiction: can occur due to the pleasurable effects
ADME of nicotine
Absorption: absorbed via inhalation, GI tract, oral mucosa, across the skin
Distribution: distributed throughout the body and rapidly gains access to the brain
Metabolism: liver
Excretion: urine
Mechanism of action of nicotine
- stimulates nicotinic receptors at synapses similar to acetylcholine
- activation of nicotinic receptors increases psychomotor activity, cognitive function, attention, and memory
Therapeutic use of nicotine
smoking cessation programs - where nicotine is administered in the form of chewing gum, transdermal patches, or buccal spray
Short term effects of smoking
- mild euphoria
- enhanced arousal
- increased ability to concentrate
- sense of relaxation
- increase in heart rate and blood pressure
- suppress appetite
Long term effects of smoking
Cardiovascular disease
- ATHEROSCLEROSIS: narrowing and hardening of arteries due to build up of plaques
- THROMBI: blood clots
Lung disease
- smokers syndrome
Cancer:
- cigarette smoke is known to increase the risk of cancer of the lung, oral cavity and throat, bladder, and uterus
Other effects of smoking
Exposure to passive smoke is associated with an increased risk of cardiovascular disease and cancer
- passive smoke = the smoke breathed in by a non-smoker when in the presence of a smoker → secondhand smoke
Smoking during pregnancy
- during pregnancy, cigarette smoke has adverse effects on the developing fetus - low birth weight and premature birth
Nicotine potential for misuse
Nicotine is a powerful reinforcer and has a high degree of misuse potential
Nicotine potential for SUD
Tolerance:
- does not appear to occur to any great extent
- most smokers will smoke to keep nicotine blood levels at a certain range
- the number of cigarettes smoked each day is the number needed to keep nicotine at this level
Withdrawal:
- withdrawal from smoking involves a number of symptoms such are irritability, restlessness, anxiety, insomnia, fatigue, and inability to concentrate
- upon awakening in the morning, the smoker is in a state of nicotine withdrawal
Addiction:
- addiction does occur and manifests as an extreme urge to smoke
Caffeine
CNS stimulant
ADME of caffeine
- absorption
- taken orally, caffeine is rapidly and completely absorbed
- blood levels of caffeine are significant at 30 minutes, and they peak 2 hours after ingestion
- distribution
- distributes to all parts of the body and freely crosses into the brain and placenta
- metabolism
- genetics determine the rate at which we metabolize and excrete caffeine
- they are rapid metabolizers and slow metabolizers
- this may explain why drinking coffee with dinner keeps some individuals awake, but not others
- elimination
- the half-life of caffeine varies among individuals from 2.5 hours to 10 hours
Mechanism of action of 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
the overall effect is stimulation of the CNS
Short-term effects of caffeine
CNS
- can produce mild mood elevation and reduce fatigue
- a small increase in performance may exist
- the flow of thought may be clearer and more rapid
- when taken by abstainers, caffeine produces nervousness and can interfere with sleep
Cardiovascular
- constriction of cerebral blood vessels increases peripheral blood flow and stimulates cardiac muscle
Respiration:
- mild stimulation of the respiratory rate and relaxation of bronchial smooth muscle occurs
Effects of caffeine in special circumstances
caffeine and smoking
- cigarette smoke increases the metabolism of caffeine, thus the duration of caffeine is shorted
caffeine and prenancy
- caffeine is not teratogenic, in that consumption of caffeine is not associated with fetal abnormalities
- metabolism of caffeine is slower in pregnant people, extending the duration of action of caffeine
Caffeine potential for misuse
misuse potential is low
caffeine does act as a mild reinforcer however, the euphoria experienced is mild in intensity
the inherent harmfulness of caffeine is very low
Caffeine potential for SUD
tolerance:
- some evidence suggests that tolerance does develop to caffeine, at least in some individuals
withdrawal:
- abrupt cessation of caffeine intake will result in mild withdrawal consisting of headache, fatigue, and drowsiness
addiction:
- mild addiction can occur
Classes of drugs used in sports
- amphetamines
- anabolic steroids
- benzodiazepines
- Blood doping and erythropoietin
- diuretics
Amphetamines in sports
produces increased alertness, a feeling of power, reduced fatigue, increased aggression, increased responsiveness, increased heart rate and blood pressure which contribute to increased endurance and speed
Cause appetite suppression
A large dose of amphetamines can lead to fatal increases in blood pressure
- as it wears off, the person experiences crashes
Anabolic steroids
increase muscle mass and strength in a large variety of sports
synthetic anabolic steroids have reduced androgenic effects but maintain the anabolic effects while testosterone has both androgenic and anabolic properties
- androgenic: effects on secondary male sex characteristics
- anabolic: the building of muscle mass
anti-catabolic
- describes processes that reduce the breakdown of proteins and muscle tissue
- anabolic steroids produce this response
athletes can train so hard that they use protein from their muscles to fuel their training
- this action is blocked by anabolic steroids, allowing athletes to maintain muscle mass
toxicities of anabolic steroids
- mood swings
- severe acne
- cardiovascular disease
- altered liver function
- reduced testosterone levels
In women:
- synthetic anabolic steroids produce some androgenic effects which include:
- increase in facial and body hair
- lowered voice
- enlarged clitoris, increased libido
- amenorrhea → absence of menstruation
Benzodiazepines
- Ativan or Valium
- reduce stress and anxiety
- impair psychomotor coordination and focus at higher doses, so the benefits are closely weighed with potential impairments in performance
Blood doping and erythropoietin
- blood doping is an effort to raise the number of blood cells by taking the blood out, storing it and then reinfection to the body’s tissues when stored blood is returned to the body there’s a sudden boost to red blood cells
- those cells carry higher than normal amounts of oxygen to muscles, enhancing performance
EPO is also used to boot the body natural production of red blood cells
- stimulates your bone marrow to make more red blood cells boosting levels of oxygen getting to your muscles and boosting performance
Diuretics
enhance excretion or salt and water through the kidneys
these drugs are used just before a competition to reduce body water ad allow the athlete to compete in a lower weight class in wrestling, weight lifting, and other sports with weight classes
also taken to hasten the excretion of other banned drugs in an attempt to avoid detection
Why ban performance enhancing drugs?
- athlete protection
- unfair advantage
