substance use and addiction Flashcards
define addiction
compulsive drug use despite harmful consequences, characterized by an inability to stop using a drug; failure to meet work, social, or family obligations; and, (depending on the drug) tolerance and withdrawal.
define dependence
refers to a physical adaptation to a substance
Tolerance/withdrawal
what is the criteria for hazardous use, how does this differ from harmful use?
hazardous use is using too much, likely to cause harm if continues at this level e.g. drinking 4 pints a day, harmful use means that the hazardous use is having a physical, psychological or social impact e.g. missing work due to hangovers
what are the 6 steps of dependence syndrome as set out by ICD-10?
- a strong desire or sense of compulsion to take the substance
- difficulties in controlling substance taking behaviour in terms of its onset, termination, or levels of use
- a physiological withdrawal state when substance use has stopped or been reduced
- evidence of tolerance: need to take more to get same effect
- progressive neglect of alternative interests
- persisting with substance use despite clear evidence of overtly harmful consequences
what difference in epidemiology in the UK is seen between alcohol problems and drug problems?
alcohol problems are widespread. drug use is widespread but dependence is concentrated
How does duration for brain entry affect addiction?
faster brain entry = more ‘rush’ and more addiction e.g crack has a faster brain entry than cocaine
what are the three main elements that contribute to drug addiction?
social and environmental factors
personal factors such as genetics and personality traits
drug factors: how addictive the substance is
which brain system is affected by alcohol?
Alcohol alters the balance between brain’s inhibitory (GABA-
A) and excitatory (glutamate) system
how is the excitatory and inhibitory system of the brain affected by alcohol? (acute)
blocks the excitatory system and enhances activity of benzodiazepene and GABA coupling so more efficient at inhibitory activity
how is the excitatory and inhibitory system of the brain affected by alcohol in the presence of alcohol? (chronic)
Upregulation of excitatory system, more NMDA receptors.
Reduced function in inhibitory system - tolerance:GABA-A receptor:
Switch in subunits to make less sensitive to alcohol
how is the excitatory and inhibitory system of the brain affected by alcohol in the absence of alcohol? (chronic)
withdrawal state:
Upregulation of excitatory system: NMDA receptor increase in Ca2+ if toxic leads to hyperexcitability (seizures) and cell death (atrophy). Reduced function of inhibitory system
How can a reduced inhibitory brain system caused by chronic alcohol use be treated?
benzodiazepines to boost GABA function
what are the three main models of addiction?
reward deficiency (positive reinforcement). overcoming adverse state (negative reinforcement). Impulsivity/ compulsivity (lack of control)
natural rewards such as food and sex, aswell as drugs of abuse increase levels of what chemical and where?
dopamine in the ventral striatum
what is the dopamine pathway often referred to as?
pleasure-reward-motivation system
what is the key modulator in the dopamine pathway?
opioid system
– particularly mu opioid that
mediates pleasurable effects (eg
of alcohol, ‘endorphin ‘rush’);
others include GABA-B, cannabinoids,
glutamate etc that are targets
for treatment
What effect does cocaine and amphetamines have on dopamine levels and how?
block reuptake of dopamine resulting in accumulation in the synapse
what affect do amphetamines have on dopamine release
enhance release
What parts of the brain are affected by withdrawal/ negative affect?
Amygdala and brainstem
What neurological structures are involved in the voluntary to habitual and compulsive drug use?
Pro frontal cortex: striata control over drug taking
Ventral (lambic/ emotional) through dorsal striatum
Why is alcohol withdrawal more dangerous than opiate withdrawal?
Worsening pattern of symptoms, hallucinations can occur at any time, Delirium tremens can set in which is a medical emergency
What is delirium tremens (DT) and how is is treat?
Auditory and visual hallucinations, confusion and disorientation, hypertension, agitation and tachycardia with severe tremor. Admission for at least 24 hours and given benzodiazepines
What medication is commonly used in hospital for acute detoxification of alcohol withdrawal in order to prevent complications?
Chlorodiazepoxide
What is the difference between ICD10 and ICD11?
11 has a harmful use category to denote single episodes of harmful use from a pattern of harmful use
Outline the effects of opioids
Relieve pain - analgesic effect
Sense of euphoria
Opioid receptors mu, delta and kappa are effected by opioid agonists or antagonists?
Both:
Agonists - heroin, methadone, fentanyl
Partial agonists - buprenorphine
Antagonists - naltrexone
What is the difference between opiates and opioids?
Opiates refer to natural opioids such as morphine and codeine. Opioids refers to all natural, semisynthetic and synthetic opioids
List three examples of natural opiates?
Opium, morphine and codeine
List three types of synthetic opioids
Fentanyl, methadone, tramadol
List three examples of semi-synthetic opioids
Heroin, hydrocodone, oxycodone
What’s are the signs of an opiate overdose?
Not moving/ cant be woken. Slow or no breathing, choking or gurgling sounds, tiny pupils, clammy or cold skin, blue lips and blue nails
What medications are given for alcohol abstinence?
Acamprosate, disulfiram, naltrexone
What medications are given for opioid abstinence?
Methadone, buprenorphine
What is the difference between ICD10 and ICD11 in terms of harmful use?
Distinction between substance dependence and harmful use is preserved
However a new category is made to denote single episode of harmful use from a pattern of harmful use
Harmful use also now includes the harm to health of others
What is the difference between the diagnostic criteria of ICD10 and ICD11 for dependancy?
The former 6 diagnostic criteria for dependence have been bundled into 3 pairs – fulfilment of one criterion is sufficient
1.Impaired control over substance use (i.e. onset, frequency, intensity, duration, termination, context)
2.Increasing precedence of substance use over other aspects of life (e.g. repeated relationship disruption, occupational or scholastic consequences, negative impact on health)
3.Physiological features indicative of neuroadaptation to the substance, (e.g. tolerance, withdrawal, use of pharmacologically similar substances to prevent or alleviate withdrawal symptoms.
Per the ICD 11 diagnostic criteria for dependecy, when can a diagnosis be made?
oThe features of dependence are usually evident over a period of at least 12 months but the diagnosis may be made if use is continuous (daily or almost daily) for at least 3 months
Which enzyme is responsible for the oxidisation of ethanol?
Alcohol dehydrogenase and then acetaldehyde dehydrogenase
What is CAGE screening?
Have you ever felt you needed to Cut down on your drinking?
2.Have people Annoyed you by criticizing your drinking?
3.Have you ever felt Guilty about drinking?
4.Have you ever felt you needed a drink first thing in the morning (Eye-opener)
What investigations are conducted in an alcohol assessment for liver damage?
Liver Fibro scan / Ultrasound
Bloods (LFT, GGT, Lipids, U&E, amylase)
Breathalyser
Urine Drug Screen
Outline the four stages of liver damage
Healthy liver
Fatty liver
Liver fibrosis
Cirrhosis
