Drug Dependence Flashcards
Define addiction
A chronic disease characterised by drug seeking and use that is compulsive or difficult to contorl, despite harmful consequences
What is the reward system of the body?
Mesolimbic system
What does the mesolimbic system do?
Connect the ventral tegmental area to the nucleus accumbens
Where is the origin of dopaminergic cell bodies and where is it found?
VGA
Midbrain
What are the stages of drug dependence?
Binge (positive reinforcement)
Withdrawal (Negative reinforcement)
Anticipation (Positive and negative reinforcement)
What can drugs cause the upregulation of?
Opioid peptide (dynorphin)
How do drugs cause the upregulation of opioid peptide?
Increased expression of cAMP which activates CREB
What does CREB do?
Upregulates expression of dynorphin
What does dynorphin do?
Negatively feedbacks to the VTA, causing less production of dopamine
What does reduced dopamine do?
Cause withdrawal effect
Symptoms of withdrawal?
Bingeing
Withdrawal
Cravings
Intoxification
Effects of alcohol abuse?
GI haemorrhage Pancreatitis Alcoholic liver disease peripheral neuropathy CV issues metabolic disorders
What happens in alcohol abuse?
Acute euphoria followed by depressed mood, slurred speech, ataxia and pupillary dilation
What does ecstasy do?
Targets 5 HT uptake and 5HT2 receptors
Affects dopamine uptake system
Causes increased levels of NT release
What effects does ecstasy have?
Psychomotor effects e.g. repetitive movements + hyper-locomotion
What does Acute MDMA toxicity include?
Body tmeperature elevation Incrreased intravascular coagulation Rhabdomyolysis Increased renal absorption of water Hyponataemia Cerebral oedema
What may overuse of MDMA lead to alteration wise in CAN?
Serotonin axon loss
What is the main agonist in cannabis?
THC (tetrahydrocannabinol)
What do cannabinoids bind to?
CB1 and CB@ receptors
Where are CB1 receptors concentrated?
CNS
most abundant CPCR in mammal brain
Where are CB2 receptors present?
peripheral organs (associated with immune system)
What effects do cannabinoids (e.g. NTS) do?
Produce mostly inhibitory effects by inhibiting glutamate and GABA release pre-synaptically
What risks does cannabis have?
Gateway drug
Long term use increases risk of developing schizophrenia and major depression
How would you manage addiction?
Detoxification Psychological support counselling Medication Evaluation and treatment for co-occurring mental health problems Long-term follow up
What management to give to alcohol addiction?
BZDs Direct GABA agonists Antiepileptic agents (carbamazepine) Selective serotonin reuptake inhibitors Thiamine
What to give for nicotine addiction?
Nicotine agonists
What to give opiate addiction?
Opioid agonist (methadone)
