Symposium 3 - Addictions Psychiatry Flashcards
Define tolerance.
Reduced responsiveness to a drug caused by previous administration
Give examples of drugs that can develop tolerance?
Opioids
Ethanol
Barbiturates
Benzodiazepines
What is dispositional tolerance?
Less drug reaches active site
What is pharmacodynamic tolerance?
Drug has less action at active site
What can cause dispositional tolerance?
decreased rate of absorption
increased rate of metabolism
increased rate of excretion
What can cause pharmacodynamic tolerance?
Down-regulation of internalisation of drug receptors
Reduced signalling
What can development of tolerance lead to?
Withdrawal symptoms –> increased response
from homeostasis compensatory mechanism
What is the withdrawal phenomenon?
Withdrawal effect of drug usually reverse of acute effect
Give an example of an acute vs withdrawal effect of a drug.
Opioid: acute = constipation, withdrawal = diarrhoea
Cocaine: cocaine = elevated mood, withdrawal = depressed mood
What is the reward pathway?
Ventral tegmental area –> nucleus accumbens –> prefrontal cortex
Dopamine = neurotransmitters
Causes sensation of pleasure/reward
Give examples of drugs of abuse that tap into reward pathway and increase dopamine?
Heroin -> increases firing rate of dopaminergic neurons
Amphetamine -> increases dopamine release
Cocaine -> inhibits dopamine uptake
Alcohol
What are the two distinct components of drug dependence?
- Physical dependence (consequence of tolerance)
2. Psychological craving (from reward pathway stimulation)
What is the most addictive drug?
Heroin
Name two classes of stimulant drugs?
Cocaine
Amphetamine
What is cocaine made from?
Coco plant
What type of cocaine is snorted or injected?
Cocaine hydrochloride
When do you get effects form cocaine?
Smoking - almost immediate
Injecting 15-30s
Snorting 3-5 mins
What are effects of cocaine?
Stimulant/euphoriant Increased alertness/energy Increased confidence/impaired judgement Lessens appetite and desire for sleep Damage to nose and airways Convulcions Respiratory failure Arrhythmias MI Hypertension Toxic confusion Paranoid psychosis
What are cocaine withdrawal effects?
Depression, irritability, agitation, craving, hyperplasia, hypersomnia
What is the difference in side effects of amphetamines?
Same as cocaine but longer lasting effects
Psychosis in heavy chronic use
Give examples of opiates.
Opium, morphine, heroin, methadone, codeine
Dihydrocodeine
What are methods of taking amphetamines?
Sniffed
Swallowed Injected
How is heroin taken?
Snorting, smoking, injection
What are side effects/signs of heroin use?
Analgesia Drowsiness and sleep Euphoria/intense pleasure Respiratory depression Cough reflex depression N&V Lowers BP Pupillary constriction Constipation
What are clinical signs of opiate overdose?
Pinpoint pupils, unreactive to light Snoring --> shallow respiration (<8 breaths/min) Bradycardia Hypotension Reduced consciousness/coma Respiratory arrest with pulse
What are signs of opiate withdrawal syndrome?
Craving, insomnia, yawning, muscle pain and cramps, increased salivary, Hal, lacrimal secretions, dilated pupils, piloerection (‘cold turkey”)
Name 2 benefits and 2 disadvantages of methadone maintenance.
benefits - reduces IV misuse
Disadvantage - decriminalise drug, allow normalisation of lifestyle, leakage to illicit market
What are effects of Ecstasy (MDMA)?
Relaxed euphoric state without hallucinations
Euphoria and then calm
Increased sociability
What are side effects of Ecstasy (MDMA)?
Nausea Dry mouth Hypertensive Pyrexia Dehydration Anxiety Drug induced psychosis
What is the most commonly used illicit drug?
Cannabis
What is the psychoactive agent in cannabis?
Tertahydrocannabinol (THC) - dissociative affect, positive affect on mood
What are the psychological effects of cannabis?
Relaxing, stimulation, euphoriant, increases sociability, increases appetite, change in perception, synaesthesias
High dose: anxiety, panic, persecutory ideation, hallucinatory activity
What are the effects of CBD?
Mild anxiolytic and antipsychotic
List ill effects if cannabis.
Respiratory problems
Toxic confusion
Exacerbation of major mental illness
Give examples of novel psychoactive substances.
NPS, “legal highs”
What are anabolic steroids?
Family of drugs comprising of testosterone and many synthetic analogues
Why do people use anabolic steroids?
Enhance muscle mass and strength, enhance appearance, reduce body fat.
What are side effects of anabolic steroids?
Skin - acne, stretch marks, baldness
Feminisation in males
Virilisation in women including hirsutism, deep voice
Increased cholesterol
Hypertension
Liver disease
What are psychological side effects of anabolic steroids?
Irritability and anger
Hypomania and mania
Depression and suicidality on withdrawal
