Drugs of Abuse Flashcards
Incentivize behaviors beneficial to reproductive fitness, such as food and sex
function
Also known as the reward pathway, plays an important role in addiction
Regulated by the neurotransmitter dopamine
Mesolimbic pathway. Includes nucleus accumbens, ventral tegmental area, and projects to the limbic system (hippocampus and amygdala)
The start of the mesolimbic pathway. Function is to produce dopamine
Projects to nucleus accumbens, limbic system (hippocampus and amygdala), and prefrontal cortex
Ventral tegmental area
Controls motor functions
Part of the mesolimbic pathway
Nucleus accumbens
Processes emotions such as fear
Part of the mesolimbic pathway
Amygdala
Drug addiction has psychological and physiological components. Treatment should address both.
Treatment overview
Separation of addict from drug
detoxification
Used in treatment of opioid addiction.
Causes slow activation of opiate receptors, decreasing high and decreasing withdrawal symptoms.
Because of competitive inhibition, concurrent heroin use will not result in a high.
Methadone
Usually a nicotine patch
Used for cigarette (nicotine) addiction
Delivers low levels of nicotine to reduce cravings and withdrawal symptoms
Nicotine replacement therapy
Form of talk therapy focused on cognitive distortions and behaviors to change thinking patterns
Broadly applicable in psychiatry, including in substance use disorders
Cognitive behavioral therapy (CBT)
“Person-centered” approach to behavior change, whereby the clinician identifies the patient’s intrinsic motivation to change and helps them address ambivalence
In contrast, more traditional methods are prescriptive in nature
Motivational interviewing
Group therapy to overcome addiction
Popular examples = Alcoholics Anonymous, Narcotics Anonymous
12 step programs
Three key ideas of 12 step programs
- Acceptance = acknowledge addiction is a problem
- Surrender = accept help offered through group and higher power
- Active Involvement = help other addicts
Recurrence of pathological drug use after abstinence
relapse
Substances that change brain function + alter perception, mood, consciousness, cognition, or behavior
psychoactive drugs
Categories of psychoactive drugs
Depressants, stimulants, hallucinogens
Decrease arousal and brain stimulation
Primarily calmative, sleep-inducing, anxiety-reducing, and anesthetizing
Include alcohol, barbiturates, and benzodiazepines
Depressants
Increase arousal and activity in the nervous system
Include caffeine, nicotine, amphetamines, and cocaine
stimulants
Cause hallucinations + changes to perception, consciousness, and thoughts
Include psilocybin, LSD, mescaline, and DMT
Hallucinogens
decrease CNS function, HR/BP, and induce sleep (similar to depressants)
Can cause death by respiratory depression
Include heroin, codeine, morphine, oxycodone
Mnemonic: T in opiates indicates they are natural, like trees
Opiates (natural) and opioids (synthetic)
Physical or mental impairment due to influence of specific drug
Example: “high” with LSD, “drunk” with alcohol
Intoxication
Two time frames of drug withdrawal:
acute and post-acute
Duration: few weeks
Characteristics: physical withdrawal symptoms
Acute withdrawal
Duration: up to 2 years
Characteristics: psychological and emotional symptoms, such as sleep difficulties, anxiety, irritability, impaired concentration
Post acute withdrawal syndrome
Disorders caused by the substance, such as disorders relating to mood, anxiety, sleep, sexual function, psychosis
Substance-induced disorders
Significant impairment in life at work/school/home due to substance use
Usage patterns = failing to meet expectations, frequent cravings
Withdrawal symptoms are common
Substance-use disorders
Begin after 4-12 hours, peak at 2 days, and improve at 4-5 days
Symptoms include hand tremors, delirium tremens, insomnia, fever
Treated with benzodiazepines
Alcohol withdrawal
One must first have reached a point of drug dependence
Abrupt discontinuation results in symptoms
drug withdrawal
Physical dependence is comprised of
Neurochemical changes = changes to neural connections, receptors, or neurotransmitters
Withdrawal symptoms = tremors, headaches, nausea, etc.
Tolerance = progressively larger doses required for the desired effect
Psychological dependence includes
Comprised of cravings, anxiety, panic, or anhedonia (lack of pleasure)
Routes of drug administration
Description: Absorption via GI system
Pharmacodynamics: Slow
Addictive potential: Low
Examples: Alcohol, pills/tablets
oral
Routes of drug administration
Description: Absorption via respiratory system
Pharmacodynamics: Fast
Addictive potential: Medium
Examples: Tobacco, cocaine, marijuana
Inhalation
Routes of drug administration
Description: Absorption through skin
Pharmacodynamics: Slow
Addictive potential: Low
Examples: Nicotine patch
Transdermal
Routes of drug administration
Description: Injection into venous blood
Pharmacodynamics: Fastest
Addictive potential: High
Examples: Heroin
Intravenous
Routes of drug administration
Description: Injection into muscle
Pharmacodynamics: Fast
Addictive potential: Low
Examples: Epinephrine
Intramuscular
Addictive potential
The faster the route of entry of a drug, the greater the addictive potential, all else being equal
Living systems maintain steady states with regards to various physiologic functions, such as temperature, digestion, circulation, etc.
homeostasis
Repeated drug use results in reduced effect of the drug
Can be attributed to principles of homeostasis
Drug tolerance
Shift in the dose-response curve → decreased sensitivity
Repeated exposure of receptor to ligand results in fewer available receptors
Receptor downregulation
More available receptors as a result of decreased exposure of receptor to ligand or antagonistic drug exposure
Receptor upregulation
Tolerance to one drug results in changes in tolerance to another drug
Usually due to a shared receptor
Cross tolerance
“Downer”
Slow down CNS
Primarily GABA receptors
Alcohol, barbiturates, benzodiazepines
depressants
“Upper”
Speed up CNS, elevate mood
Primarily dopamine receptors
Caffeine, amphetamines, methamphetamines, cocaine, nicotine
stimulants
Hallucinations, altered perceptions
Altered mental status, perception changes
5HT serotonin receptors
Psilocybin, LSD, mescaline, DMT
Hallucinogens
Increased analgesic effects, similar to but NOT depressants
Decrease sensation of pain
Opioid receptors (normally bind to endorphins)
Heroin, codeine, morphine, oxycodone
Opioids/opiates
