Substance Misuse & Addictions Flashcards

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1
Q

What 2 distinct mechanisms does the basic science of substance misuse suggest?

A

Tolerance (the basis of physical dependence)

Reward centre (the basis of psychological craving)

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2
Q

What is tolerance?

A

“Reduced responsiveness to a drug caused by previous administration”

Develops in response to many types of drug
eg opioids, ethanol, barbiturates, benzodiazepines

An example of homeostasis-the body likes things the way they were

Mechanisms underlying tolerance can vary

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3
Q

What are the mechanisms of tolerance and some examples?

A

Dispositional=less drug reaches the active site, eg
- decreased rate of absorption
- increased rate of metabolism to inactive metabolites
- decreased rate of metabolism to active metabolites
- increased rate of excretion

Pharmacodynamic (aka tissue or functional tolerance) = site of action is less affected by the drug
- down-regulation or internalisation of drug receptors
- reduced signalling down stream of drug
receptors
- some other compensatory mechanism

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4
Q

When does tolerance become dependence?

A

Development of tolerance may also lead to withdrawal symptoms

Development of tolerance will in itself cause dependence – have to keep taking the drug to achieve a normal state-as if not will be imbalance between drug effect and adaptive response

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5
Q

What is the withdrawal phenomena?

A

Withdrawal effect of a drug is usually the reverse of the acute effect

Tolerance & dependence are closely linked

Development of tolerance may lead to physical dependence in order to avoid the (unwelcome) withdrawal effects

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6
Q

What are the acute effects and withdrawal effects of:

  1. Opioid
  2. Barbiturate
  3. Cocaine?
A
  1. constipation-diarrhoea
  2. anticonvulsant-convulsions
  3. elevated mood-depressed mood
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7
Q

What is the reward pathway and how has it evolved?

A

The reward pathway:
- Neurones project from the ventral tegmental area to the nucleus accumbens & prefrontal cortex
- When VTA neurones are stimulated they release dopamine is released
- This causes a sensation of pleasure/reward

Why has the reward pathway evolved?
The reward pathway is normally activated by eating, drinking and sex
It therefore encourages those “healthy” behaviours that lead to propagation of your genes

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8
Q

How do some drugs of abuse affect reward centres?

A

Some drugs of abuse tap into the reward pathway and increase dopamine levels eg
- heroin increases firing rate of dopaminergic neurones
- amphetamine increases dopamine release
- cocaine inhibits dopamine uptake
- alcohol

This produces the psychological component of addiction - “craving”

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9
Q

What 2 distinct components of drug dependence have been shown in animal studies?

A

Physical dependence which develops as a consequence of tolerance to the drug

Psychological craving which is a result of stimulation of the reward pathways in the brain

In humans it is almost certainly more complex
eg discriminative (cue) effects

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10
Q

What are some examples of stimulants that are abused?

A

Cocaine
Amphetamine
Methamphetamine
Methylphenidate (prescribed for ADHD-may misuse it if they are prescribed it)

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11
Q

What is the most potent natural stimulant?

A

Cocaine-extracted from leaves of coca plant

Cocaine (powder) and crack cocaine (smoked)
Crack produced by mixing cocaine with a base (sodium bicarbonate) and purified

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12
Q

How does cocaine work?

A

Monoamine reuptake inhibitor – dopamine,serotonin,noradrenaline increase

  • Makes dopamine more available in the presynaptic space-so have sensation of rush of dopamine
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13
Q

What are the effects of cocaine and how long do different modes of taking it take effect?

A

Depends on dose and rate of entry to the brain
smoking - almost immediate
injecting - 15 to 30 secs
snorting - 3 to 5 mins
the effects of crack smoking are very intense but quickly over ( 15 mins)

EFFECTS
stimulant and euphoriant

Anaesthetic effect

Hypersensitive

increased alertness and energy

increased confidence and impaired judgement

lessens appetite and desire for sleep

If mixed with alcohol - cocaethylene-almost like cocaine with longer half life

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14
Q

What are the serious effects of cocaine?

A

damage to nose and airways (consistent vasoconstriction damages nasal septum)

convulsions with respiratory failure

cardiac arrhythmia’s and MI

hypertension and CVA

toxic confusion

paranoid psychosis

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15
Q

What are the cocaine withdrawal effects?

A

Depression
Irritability
Agitation
Craving
Hyperphagia
Hypersomnia

Broadly opposite of drug effect

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16
Q

How is amphetamine taken and what are the effects of taking it?

A

Sniffed, swallowed or injected

Effects similar to cocaine but longer lasting

Toxic confusion occasionally with convulsions and death

Amphetamine psychosis in heavy chronic use

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17
Q

What are some examples of opiates?

A

Opium
Morphine
Heroin (diamorphine)
Methadone
Codeine and dihydrocodeine

They’re all broadly, opiate agonists, often changing by exactly what opiate receptors they are hitting and half life issues as well

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18
Q

Heroine is available as what and what may it be presented as?

A

Available as diamorphine or as diamorphine hydrochloride

May be presented as powder or as an almost tar like substance

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19
Q

How can heroin be taken?

A

Taken by:
- Snorting ( not common in UK)
- Smoking(chasing the dragon)
- Injection (cultural or tolerance reasons)

Smoking is safest, injecting the most dangerous method of use

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20
Q

Via what receptors does heroin act and what is its half life?

A

Opiod agonist
Acts via mu (principally)
Acts principally via Mu ,Delta and Kappa receptors

Kappa and Delta – analgesia
Mu – mood effects, analgesia and euphoria

Half life of 30mins – multiple administrations needed if dependant ( increased risk) - subjective effect of approx. 4hrs

Sleep disturbed, acute withdrawals in the middle of the night etc

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21
Q

What are the effects of heroin and what can happen in an overdose of it?

A

Analgesia
Emotional analgesia
Nausea initially
Euphoria
Pin point pupils
Itching/sweating
Constipation
Decreased libido/menstrual irregularities
Reduced cough reflex

OVERDOSE:
Respiratory depression
Snoring indicates risk
Bradycardia
Hypotension
Death

Risk increased if mixed with other respiratory depressants – alcohol, benzodiazepines etc

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22
Q

What is used in a Heroin overdose?

A

Naloxone – opiate antagonist
National Naloxone Programme

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23
Q

What are the side effects of opiates?

A

First time - nausea/vomiting and headache

Medium term – phlebitis
-endocarditis
-Injection injuries/consequences (BBVs)
- Anorexia
- Constipation

Longer term - tolerance
- Withdrawal
- Social and health problems

BBV-Hep C most common

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24
Q

What are the signs of opiate withdrawal syndrome?

A

craving
insomnia
yawning
muscle pain and cramps
increased salivary, nasal and lacrimal secretions
dilated pupils
piloerection (hence ‘cold turkey’)

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25
Q

What is the role of methadone maintenance and what is its downfall?

A

Decriminalises drug use & allows normalisation of lifestyle

Reduces iv misuse

Leakage on to the illicit market

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26
Q

What is another name for diazepam?

A

Valium

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27
Q

Xanax is also known as?

A

Alprazolam

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28
Q

Benzodiazepines: What kind of agonists are they?

A

GABA agonists

Anxiolytics, sedatives

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29
Q

Ecstasy (MDMA): what are its effects?

A

Relaxed euphoric state without hallucinations

Majority of all ‘ecstasy tabs.’ contain no MDMA

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30
Q

What are the side effects of ecstasy?

A

Nausea and dry mouth
Increased blood pressure and temperature
In clubs users risk dehydration
Large doses can cause anxiety and panic
Drug induced psychosis

31
Q

What is the psychoactive component of cannabis?

A

THC

32
Q

What are the effects of cannabis?

A

Relaxing or stimulating, euphoriant , increases sociability and hilarity, increases appetite, changes in time perception, synaesthesia

In higher dose - anxiety , panic , persecutory ideation, hallucinatory activity

respiratory problems as with tobacco
toxic confusion
exacerbation of major mental illness
cannabis psychosis

33
Q

What are examples of performance & image enhancing drugs?

A

Anabolic Steroids
Growth Hormone
Injectable Tanning agents eg Melotan

Risk from drug effect, route of administration (IM/IV) and route of access

34
Q

What are anabolic (androgenic) steroids and when are they legitimately prescribed?

A

Anabolic steroids or steroids for brevity

Family of drugs comprising testosterone and many synthetic analogues

Legitimately prescribed in hypogonadism, muscular dystrophy, various anaemias, wasting in AIDS

Muscle hypertrophy from steroid use is particularly marked in the upper body in the pectoralis, deltoid, trapezius, and biceps

35
Q

What are the side effects of steroids?

A

Skin – acne, stretch marks, baldness

Feminisation in males with hypogonadism and gynaecomastia (occasioning use of anti-oestrogens)

Virilisation in women including hirsutism, deep voice, clitoral enlargement, menstrual irregularities, hair thinning

Cardiovascular – increased cholesterol and hypertension

Growth deficits due to premature closure of epiphyses

Liver Disease – cholestatic jaundice, liver tumours

36
Q

What are the psychological side effects of steroids?

A

Irritability and anger – ‘roid rage’

Hypomania and mania

Depression and suicidality on withdrawal

37
Q

What are the treatment options for drug misuse?

A

What drug
What combinations
Harmful/hazardous use?
Dependency?
Risk

Biopychosocial treatment packages
Strong emphasis on risk reduction
Abstinence vs Harm reduction debates
Treatment is effective

38
Q

What can be done to reduce drug related deaths?

A

National Public Health crisis

Optimise treatment
Reduce barriers to treatment
Public Health rather than criminal justice response
Research
National Naloxone Programme

39
Q

What are the most worrying trends in harm in relation to alcohol?

A

Men
Older people
Home drinking
Long term health conditions

40
Q

What were some actions put in place to tackle alcohol issues?

A
  • Minimum unit pricing
  • Ban on milti buy discounts
  • Age checks
41
Q

What are the stages of damage of alcohol abuse on the liver?

A

Abuse of alcohol can cause hepatic steatosis or alcoholic hepatitis (these can return to a healthy liver with abstinence)

The continues abuse of alcohol then leads to hepatic cirrhosis

Healthy liver—-Fatty liver—-Cirrhosis of liver

42
Q

Most heavy drinkers will have fatty liver, what percentage of those with alcoholic fatty liver progresses to cirrhosis?

A

20%

Alcohol Abstinence improves Fatty Liver to normal

43
Q

What are the signs of acute alcoholic hepatitis?

A

Alcohol intake > 6u / day

Jaundice with Bilirubin > 80mg/dl

No other aetiology for Liver inflammation

Very high Mortality / No specific treatment yet

44
Q

What scoring system is used for Alcoholic Hepatitis?

A

GAHS score

Looks at Age, urea, WCC, INR and bilirubin

45
Q

What does it mean if GAHS ≥ 9?

A

There is a marked rise in mortality

30 day mortality
Without steroids 48%
With steroids 22%

84 day mortality
Without steroids 62%
With steroids 41%

46
Q

Why are alcohol and malnutrition linked?

A

60 % of chronic abusers have malnutrition

Most of the calories is from Alcohol

Total energy intake is reduced:
Nausea & Vomiting
Abdo pain
Diarrhoea

47
Q

What are the reasons for mortality in alcoholic cirrhosis?

A

75% die of Liver decompensation

20-25% Hepatocellular cancer sequelae

48
Q

What are the indications for Liver transplantation?

A

ARLD is the most common indication

Resistant complications of Cirrhosis
Jaundice
Ascites
Encephalopathy
Coagulopathy

Hepatocellular Cancer

49
Q

Is cirrhosis rare in teenagers?

A

YES its rare

Deranged LFTs are common especially in obese teenagers

50
Q

What is exposure to alcohol <14 years strongly associated with?

A

Later alcohol abuse and dependence

51
Q

When does alcoholic ketoacidosis tend to occur?

A

Tends to occur the day after a massive binge. Lipolysis tends to be increased because of the increased levels of cortisol and catecholamines, caused by the extra stress placed on the patient’s body from the alcohol.

The Lipolysis contributes to an abundance of FFA, which in turn sees some diverted to ketone production (the three ketones you will see mentioned are acetoacetate, beta-hydroxybutyrate, and acetone – alcoholic ketoacidosis tends to involve excess beta-hydroxybutyrate) .

The metabolism of ethanol raises NADH/NAD which in turn impairs hepatic gluconeogenesis and the metabolism of lactate.

So the patient has impaired ability to make glucose, or metabolise lactate, driving the hypoglycaemia and acidosis.

52
Q

How do you stabilise a patient with alcoholic ketoacidosis?

A

IV fluids

Vit B1 THIAMINE (Pabrinex)

You latterly give some glucose once they have had Pabrinex, and use a symptom triggered diazepam scoring chart to help manage alcohol withdrawal.

53
Q

What are the signs of Wernicke’s?

A

CONFUSION

GATE ATAXIA

OPTHALMOPLEGIA

54
Q

What can Wernicke’s progress to that is IRREVERSIBLE?

A

KORSAKOFF’S

55
Q

What can a deficiency in thiamine cause?

A

Can cause a build up of lactic acid, amongst other things (chronic alcohol misusers are prone to be deficient in as alcohol blocks duodenal uptake of thiamine and interferes with thiamine storage and conversion).

56
Q

Lack of activity of alpha ketoglutarate dehydrogenase in particular has been linked to what?

A

Mitochondrial damage causing cellular necrosis, and triggering apoptosis (cell death) – cells in the cerebellum are particularly sensitive to this (hence the motor control issues).

57
Q

What should you do if you ever see an unexplained lactic acidosis?

A

Thiamine (or its I.V. formulation Pabrinex) has very little downside to administration (there is the very small chance of anaphylaxis) – if you ever see an unexplained lactic acidosis, give thiamine.

If you do not, and give glucose without it in the malnourished or thiamine deficient patient, you risk driving Wernicke’s Encephalopathy.

58
Q

The metabolite of ethanol, …, is thought to be particularly toxic especially to hepatic proteins

A

Acetaldehyde

59
Q

What are the presentations of fatty liver & alcoholic hepatitis (think bloods)?

A

With Fatty Liver (alcoholic steatosis) – there is often a subclinical hyperbilirubinaemia and mild elevation of transaminases (AST/ALT). Gamma GT is elevated in a majority of patients.

With Alcoholic Hepatitis – a diversity of presentations from jaundice, anaemia, and leucocytosis. The hepatic enzymes tend to present in a ratio of AST: ALT >2 (should normally be <1).

60
Q

What are some specific markers of intracellular damage of the liver?

A

ALT and AST are markers of intracellular damage; gGT is a sensitive but non-specific marker involved with oxidative stress on the liver.

61
Q

What is harmful use of alcohol defined as?

A

Harmful Use – pattern of use causing damage to physical or mental health. Use >1 month or repeatedly over 12 months

62
Q

What is alcohol dependance?

A

Dependence – 3 or more of the following for >1month or repeatedly over 12 months:

Cravings/compulsions to take
Difficulty controlling use
Primacy
Increased tolerance
Physiological withdrawal on reduction/cessation
Persistence despite harmful consequences

63
Q

What is a withdrawel state?

A

Withdrawal State – Group of symptoms of variable clustering and severity on complete/relative withdrawal of a psychoactive substance, after persistent use of that substance

64
Q

What can occur usually 48-72 hrs after alcohol is stopped and presents with Profound confusion, tremor, agitation, hallucinations, delusions, sleeplessness, autonomic over-activity?

A

DELIRIUM TREMENS

65
Q

How does Wernicke’s encephalopathy present?

A

Confusion, ataxia, opthalmoplegia, nystagmus

66
Q

How does Korsakoff’s psychosis present?

A

Prominent impairment of recent and remote memory, preservation of immediate recall, no general cognitive impairment, retrograde and anterograde memory, impaired learning and disorientation, may exhibit nystagmus and ataxia

67
Q

Wernicke’s & Korsakoff’s are caused by what?

A

Caused by thiamine deficiency

  • Poor intake and absorption, poor hepatic function, increased requirement for alcohol metabolism
68
Q

What screening tool is used for alcohol abuse?

A

CAGE (2 or more = likely alcohol problem)

Have you tried to Cut down?
Have you felt Annoyed by people criticising your drinking?
Have you felt Guilty about drinking?
Have you felt the need to have an Eye-opener?

69
Q

Apart from CAGE what other screening tools are available in the context of alcohol?

A

AUDIT (Alcohol Use Disorders Identification Test)

FAST (4 questions)

PAT (Paddington Alcohol Test; used in A&Es)

70
Q

How can prevention of Wernicke-Korsakoff Syndrome be done?

A

THIAMINE

71
Q

What drugs are used to manage alcohol withdrawel?

A

Benzodiazepines, commonly Chlordiazepoxide

72
Q

What drugs are available as aversion/deterrence?

A

Disulfiram (Antabuse)

73
Q

What alcohol anti craving meds are available?

A

Acamprosate (Campral)

Naltrexone

Nalmefene

(Baclofen)

74
Q

What is intoxication?

A

The pathological state produced by a drug, serum, alcohol, or any toxic substance; poisoning

  • Impaired attention and judgement, unsteadiness, flushing, nystagmus, mood instability, disinhibition, slurring, stupor, unconsciousness