Addictions Flashcards
What are the 2 mechanisms responsible for substance misuse?
Tolerance
Reward centre
What is tolerance?
Reduced responsiveness to drug caused by previous administration
What is dispositional tolerance?
Less drug reaches the active site
What is pharmacodynamic tolerance?
Drug has less action at the active site
What causes increased dispositional tolerance?
Less drug absorbed
Drug metabolised faster
More drug excreted
What causes increased pharmacodynamic tolerance?
Fewer drug receptors
Less efficient drug receptors
Why can tolerance lead to withdrawal symptoms?
A drug effect which disrupts homeostasis will lead to an adaptive response, if the drug is stopped the adaptive response will suddenly be too much for the body
How does the body change in an adaptive response?
Change number of receptors
Change efficacy of receptors
What is the withdrawal phenomena?
The withdrawal effect of a drug is the opposite of the acute effect
What are the acute and withdrawal effects of opioids?
Acute - constipation
Withdrawal - diarrhoea
What are the acute and withdrawal effects of barbiturates?
Acute - anticonvulsant
Withdrawal - convulsions
Where is the reward pathway in the brain?
Ventral tegmental area to the nucleus accumbens and prefrontal cortex
What are the 2 most common stimulants?
Cocaine
Amphetamine
What are effects of cocaine on mood?
Stimulant and euphoriant
Increased alertness and energy
Increased confidence and impaired judgement
Lessen appetite and need for sleept
What are physical effects of cocaine?
Damage to nose and airways Convulsions with resp failure Cardiac arrhythmias and MI Hypertension Toxic confusion Paranoid psychosis
What are withdrawal effects of cocaine?
Depression Irritability Agitation Craving Hyperphagia Hypersomnia
What are acute effects of amphetamine?
Toxic confusion occasionally with convulsions and death
Psychosis in chronic use
What are slang terms for heroin?
H
Gear
Smack
Brown
What are effects of opiates?
Analgesia Drowsiness Mood change - euphoria Respiratory depression Cough reflex depression Sensitisation of the labyrinth Decreased sympathetic outflow Lowering body temp Pupillary constriction Constipation
What are symptoms of opiate withdrawal?
Craving Insomnia Yawning Muscle pain and cramps Increased salivary secretions Dilated pupils Piloerection
What are effects of ecstasy?
Euphoria followed by feelings of calm
Increased sociability
Inability to distinguish between what is and isnt desirable
Effects after 20 mins lasting 2-4 hours
What are side effects of ecstasy?
Nausea and dry mouth Increased blood pressure and temperature Dehydration Anxiety and panic Psychosis Liver and brain damage
What are side effects of cannabis?
Resp problems such as with tobacco
Toxic confusion
Exacerbation of major mental illness
