Addictions Psychiatry

Question 1

What is the definition of tolerance?

Answer 1

Reduced responsiveness to a drug caused by previous administration

Question 2

Describe the two types of tolerance

Answer 2

Dispositional tolerance - less drug reaches the active site

Pharmodynamic tolerance - drug has less action at the active site

Question 3

Describe the mechanisms of dispositional tolerance

Answer 3

• Decreased rate of absorption
• Increased rate of metabolism to inactive metabolites
• Decreased rate of metabolism to active metabolites
• Increased rate of excretion

Question 4

Describe the mechanisms of pharmacodynamic tolerance

Answer 4

• Down-regulation or internalisation of drug receptors
• Reduced signalling down stream of drug receptors
• Other compensatory mechanisms

Question 5

Describe the reward pathway

Answer 5

• Neurones project from the ventral tegmental area to the nucleus accumbens and prefrontal cortex
• When VTA neurones are stimulated dopamine is released
• This causes a sensation of pleasure/reward

Question 6

Which drugs of abuse tap into the reward pathway?

Answer 6

Heroin, amphetamine, cocaine and alcohol

Question 7

Give two examples of drugs that are stimulants

Answer 7

Cocaine and amphetamine

Question 8

What are the effects of cocaine?

Answer 8

• Stimulant and euphoriant
• Increased alertness and energy
• Increased confidence and impaired judgement
• Lessens appetite and desire for sleep

Question 9

What are the potential consequences of cocaine use?

Answer 9

• Damage to nose and airways
• Convulsions with respiratory failure
• Cardiac arryhthmias and MI
• Hypertension and CVA
• Toxic confusion
• Paranoid psychosis

Question 10

What are the withdrawal effects of cocaine?

Answer 10

Depression, irritability, agitation, craving, hyperphagia and hypersomnia

Question 11

What are the potential consequences of amphetamine use?

Answer 11

• Toxic confusion
• Convulsions
• Death
• Psychosis

Question 12

Give examples of opiates

Answer 12

Opium, morphine, heroin, methadone, codeine and dihydrocodeine

Question 13

What are the effects of heroin?

Answer 13

Analgesia, drowsiness, sleep, mood change, respiratory depression, cough reflex depression, nausea, vomiting, bradycardia, hypotension, lowering of body temperature, pupillary constriction and constipation

Question 14

What are the side effects of opiates?

Answer 14

• First time: nausea, vomiting and headache
• Medium term: phlebitis, anorexia and constipation
• Longer term: tolerance, withdrawal and social/health problems

Question 15

What are the symptoms of opiate withdrawal?

Answer 15

Cravings, insomnia, yawning, muscle pain, cramps, increased salivary/nasal/lacrimal secretions, dilated pupils and piloerection

Question 16

What are the effects of ectasy?

Answer 16

• Relaxed euphoric state without hallucinations
• Increased sociability
• Inability to distinguish between what is and isn’t desirable

Question 17

What are the potential side effects of ectasy?

Answer 17

Nausea, dry mouth, increased blood pressure and temperature, dehydration (club users), anxiety, panic and psychosis

Question 18

What are the psychological effects of cannabis?

Answer 18

• Relaxing or stimulating, euphoriant, increased appetite, changes in time perception and synaesthesia
• Higher doses: anxiety, panic, persecutory ideation and hallucinatory activity

Question 19

What are the potential ill effects of cannabis?

Answer 19

Respiratory problems, toxic confusion, exacerbation of major mental illness and psychosis?

Question 20

What are the potential side effects of steroid use?

Answer 20

• Acne, stretch marks, baldness, feminisation in males (hypogonadism and gynaecomastia) and virilisation in women (hirsutism, deep voice, clitoral enlargement, menstrual irregularities and hair thinning
• Cardio: increased cholesterol and hypertension
• Growth deficits
• Liver: cholestatic jaundice and liver tumours
• Psychological: irritable, anger, hypomania, mania, depression and suicidality on withdrawal