Drug Dependence and Tolerance

Question 1

Give 3 criteria the ICD 10 gives for drug dependency

Answer 1

• desire or sense of compulsion
• difficulties in controlling substance abuse
• a physiological withdrawal state
• tolerance
• prioritising use
• persisting with substance use despite consequences

Question 2

Why do people take drugs?

Answer 2

• Psychological addiction - rewarding pathways

- Physical addiction - self-medicate withdrawal symptoms

Question 3

What do drugs do to the brain?

Answer 3

Activate reward systems - if you enjoy something, you will repeat the same activity

Question 4

What is the effect of cocaine in the brain?

Answer 4

• Blocks the Dopamine reuptake transporters on the presynaptic membrane
• more DA will stay in the synapse and so will stimulate D receptors more often

Question 5

What is the effect of amphetamine in the brain?

Answer 5

• Get inside the cell via Dopamine transporters and displace DA from the synaptic vesicles
• They are lipophilic and cationic so can get into cells and IC organelles quite easily

Question 6

Name some CNS stimulants

Answer 6

• Amphetamine
• Cocaine
• Nicotine
• Caffeine

Question 7

Name some CNS depressants

Answer 7

• Alcohol
• Opioids
• Barbiturates
• BZDs
• Volatile solvents

Question 8

Name some Hallucinogens

Answer 8

• LSD
• Ecstacy
• Ketamine
• Cannabis

Question 9

What effects do drugs have on the body?

Answer 9

• Cardiovascular - increased BP, HR, risk of respiratory arrest
• Liver disease
• Neurotoxicity
• Behaviour - depression, dementia, psychosis, anxiety
• Anorectic effects (appetite suppressants)

Question 10

What treatments are there for dependence?

Answer 10

• mainly psychological
• Disulfiram for alcohol - blocks ALDH enzyme, causes a build up of acetyladehyde ,alomg you feel sick
• Methadone replacement and opioid antagonists for Heroin - act on mu opioid receptors

Question 11

What other addictive behaviours are there?

Answer 11

• Gambling
• Sex
• Over-eating
• exercise

(all activate DA systems)