Substance use disorder: alcohol

Question 1

What is the pathophysiology of substance use disorder?

Answer 1

State of distress

• –> distress-reducing behaviour –> behaviour itself is damaging/diabling
• e.g. self harm, substance use, disordered eating, compulsive rituals
• –> temporary relied leads to negative reinforcement
• –> urge
• –> repetition –> habit-formation –> compulsion

Dopaminergic cirucits are invovled, limbic system learns this as a response to distress.

Someone needs to choose to stop this behaviour and it is difficult.

Question 2

What is the ICD-10 criteria for dependance syndrome?

Answer 2

1. Compulsion - strong desire to take the substance
2. Control - difficulties in controlling substance-taking behaviour (onset, termination, levels)
3. Withdrawal - physiological withdrawal when substance use has ceased or have been reduced
4. Tolerance - increased doses required to achieve originally porduced effects by lower doses
5. Salience - little alternative pleasure or interests due to psychoactive substance use, increased time needed to obtain or take the substance or to recover from its effects
6. Persistance - with substance use despite clear evidence of overtly harmful consequences, such as harm to liver through excessive drinking, depressive mood states consequent to periods of heavy substance use or drug-related impairment of cognitive functioning

3 or more of the following manifestations should have occurred together for at >1 month or, if persisting for periods of <1 month, should have occurred together repeatedly within a 12-month period.

Question 3

Which drugs target GABA-A?

Answer 3

• Alcohol
• Z-drugs
• Benzodiazepines
• Gamma hydroxybutyrate (GHB)
• Baclofen (GABA-B)

Question 4

Which are long vs short-acting benzodiazepines?

Answer 4

Diazepam, clonazepam, chlordiazepoxide - long acting

Midazolam, lorazepam - short acting

Question 5

What is the MOA of benzodiazepines?

Answer 5

• Positive allosteric modulators of GABA-A
• When it binds, the receptor has greater affinity for GABA
• Increased flow of Cl- channels occyrs hence hyperpolarisation of the post-syanaptic membrane
• Hence neurone has reduced excitability

Question 6

Do benzodiazepines cause tolerance or dependence?

Answer 6

Both

Question 7

What are the withdrawal symptoms of benzodiazepines?

Answer 7

• Anxiety
• Irritability
• Restlessness
• Tremor
• Sweating
• Insomnia
• Appetite disturbance
• Confusion

RISK: convulsions and psychosis

Question 8

What does toxixity of benzodiazepines cause?

Answer 8

• Drowsiness
• Ataxia
• Slurred speech
• Reduced consciousness
• Hypotension
• Bradycardia

Question 9

How can overdose of benzodiazepines present? What is the antidote?

Answer 9

• Overdose - respiratory depression
• Antidote- Flumazenil

Question 10

How is benzodiazepine dependence managed?

Answer 10

1. GP/Addiction services
2. Convert to diazepam equivalent dose for once daily dosing (up to 40mg)
3. Very slowly reduce the does e.g. <10% every 2 weeks

Question 11

What is the stages of change model?

Answer 11