Addictions Psychiatry Flashcards
(20 cards)
What is the definition of tolerance?
Reduced responsiveness to a drug caused by previous administration
Describe the two types of tolerance
Dispositional tolerance - less drug reaches the active site
Pharmodynamic tolerance - drug has less action at the active site
Describe the mechanisms of dispositional tolerance
- Decreased rate of absorption
- Increased rate of metabolism to inactive metabolites
- Decreased rate of metabolism to active metabolites
- Increased rate of excretion
Describe the mechanisms of pharmacodynamic tolerance
- Down-regulation or internalisation of drug receptors
- Reduced signalling down stream of drug receptors
- Other compensatory mechanisms
Describe the reward pathway
- 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
Which drugs of abuse tap into the reward pathway?
Heroin, amphetamine, cocaine and alcohol
Give two examples of drugs that are stimulants
Cocaine and amphetamine
What are the effects of cocaine?
- Stimulant and euphoriant
- Increased alertness and energy
- Increased confidence and impaired judgement
- Lessens appetite and desire for sleep
What are the potential consequences of cocaine use?
- Damage to nose and airways
- Convulsions with respiratory failure
- Cardiac arryhthmias and MI
- Hypertension and CVA
- Toxic confusion
- Paranoid psychosis
What are the withdrawal effects of cocaine?
Depression, irritability, agitation, craving, hyperphagia and hypersomnia
What are the potential consequences of amphetamine use?
- Toxic confusion
- Convulsions
- Death
- Psychosis
Give examples of opiates
Opium, morphine, heroin, methadone, codeine and dihydrocodeine
What are the effects of heroin?
Analgesia, drowsiness, sleep, mood change, respiratory depression, cough reflex depression, nausea, vomiting, bradycardia, hypotension, lowering of body temperature, pupillary constriction and constipation
What are the side effects of opiates?
- First time: nausea, vomiting and headache
- Medium term: phlebitis, anorexia and constipation
- Longer term: tolerance, withdrawal and social/health problems
What are the symptoms of opiate withdrawal?
Cravings, insomnia, yawning, muscle pain, cramps, increased salivary/nasal/lacrimal secretions, dilated pupils and piloerection
What are the effects of ectasy?
- Relaxed euphoric state without hallucinations
- Increased sociability
- Inability to distinguish between what is and isn’t desirable
What are the potential side effects of ectasy?
Nausea, dry mouth, increased blood pressure and temperature, dehydration (club users), anxiety, panic and psychosis
What are the psychological effects of cannabis?
- Relaxing or stimulating, euphoriant, increased appetite, changes in time perception and synaesthesia
- Higher doses: anxiety, panic, persecutory ideation and hallucinatory activity
What are the potential ill effects of cannabis?
Respiratory problems, toxic confusion, exacerbation of major mental illness and psychosis?
What are the potential side effects of steroid use?
- 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
