Addiction psychiatry Flashcards
What are the 2 distinct mechanism which drive substance misuse?
Tolerance
Reward centre
What is tolerance?
Reduced responsiveness to a drug caused by previous administration
What causes dispositional tolerance?
Less drug reaches the active site
Less drug absorbed
Drug metabolised faster
More drug excreted
What causes pharmacodynamic tolerance?
Drug has less action at the active site
Fewer drug receptors
Less efficient drug receptors
Why does tolerance sometimes lead to dependence?
Development of tolerance may lead to withdrawal symptoms
What are the acute and withdrawal effects of opioids?
Constipation
Diarrhoea
What is the reward pathway?
Neurones project from the ventral tegmental area to the nucleus accumbens & prefrontal cortex
What is released when VTA neurones are stimulated?
Dopamine
How does drug abuse relate to reward centres?
Some drugs of abuse tap into the reward pathway and increase dopamine levels
This produces the psychological component of addiction
How does heroin affect reward centres?
Increase firing rate of dopaminergic neurones
How does amphetamine affect reward centres?
Increased dopamine release
How does cocaine affect reward centres?
Inhibits dopamine uptake
Which is the most potent natural stimulant?
Cocaine
How quickly does cocaine take effect?
Smoking - almost immediate
Injecting - 15 to 30 secs
Snorting - 3 to 5 mins
What are the effects of cocaine?
Stimulant/euphoriant Alertness Energy Confidence Impaired judgement Lessens appetite and desire for sleep
What are some adverse effects of cocaine?
Damage to nose and airways Convulsions with respiratory failure Cardiac arrhythmia's and MI Hypertension and CVA Toxic confusion Paranoid psychosis
What are some withdrawal effects of cocaine?
Depression Irritability Agitation Craving Hyperphagia Hypersomnia
Does amphetamine last longer or shorter than cocaine?
Longer
What are some commonly abused opiates?
Opium Morphine Heroin Methadone Codeine Dihydrocodeine
What does the phrase “chasing the dragon refer to?”?
Smoking heroin
What are some adverse effects of heroin use?
Respiratory arrest with a pulse Pinpoint pupils Unreactive to light Snoring giving way to shallow respiration Bradycardia Hypotension Reduced consciousness/coma
What are some adverse effect of opiates?
Nausea Vomiting Headache Phlebitis Anorexia Constipation Tolerance Withdrawal Social
What are some characteristics of opiate withdrawal syndrome?
Craving Insomnia Yawning Muscle pain and cramps Increased salivary and nasal secretions Dilated pupils Piloerection
Almost half of all eccies contain no MDMA. What else do they contain?
Nil active
LSD
Amphetamine
Ketamine
What are some common effects of MDMA?
Euphoria followed by feeling of calm
Increased sociability
Inability to distinguish between what is and isn’t desirable
What are some adverse side effects of MDMA?
Nausea Dry mouth/dehydration Increased BP and temp Anxiety Panic Psychosis
What is another name for Novel Psychoactive Substances (NPS)?
Legal highs
When might anabolic (androgenic) steroids be legitimately prescribed?
Hypogonadism
Muscular dystrophy
Various anaemias
Wasting in AIDS
Muscle hypertrophy from steroid use is particularly marked in which areas?
Pectoralis
Deltoid
Trapezius
Biceps
What are some skin effects of steroid use?
Acne
Stretch marks
Baldness
How might steroid use adversely affect males?
Feminisation
Hypogonadism
Gynaecomastia
How might steroid use adversely affect women?
Virilisation Hirsutism Deep voice Clitoral enlargement Menstrual irregularities Hair thinning
How does steroid use affect the CVS?
Increased cholesterol
Hypertension
How does steroid use affect growth?
Growth deficits due to premature closure of epiphyses
How does steroid use affect the liver?
Cholestatic jaundice
Liver tumours
What are some psych side effects of steroid use?
Irritability
Hypomania/mania
Depression on withdrawal
How is naloxone used?
Opiate antagonist
Reverses effect of opiates
