Addiction- modification antagonist and agonist substitution Flashcards
How do these work?
Mimic or block the effects of particular substances on the brain
What do agonist drugs do?
Enhances activity
An agonist is a chemical that binds to a postsynaptic receptor and activates that receptor to produce a response. In the case of medication, agonists are designed to imitate the action of another substance such as heroin.
What do antagoist drugs do?
Block receptor sites
What is the agonist substitution?
Methadone
What does methadone agonist do?
Used during an addiction to opioid
When users take heroin it causes an excess of dopamine meaning receptor sites become less sensitive. Thus neurons adapt to high levels of dopamine by releasing less so less pleasurable effect and avoidance of withdrawal
What is methadone?
Replacement for heroin
This occupies the dopamine receptors in the brain mimicking the heroin without the high activating dopamine receptors so reducing the symptoms of withdrawal
-Thus meaning it doesn’t have the same euphoric rush that’s associated with jerion (meaning patients don’t have extreme highs and lows)
-So they will become addicted to methadone and not extremience uncontrolled compulsivity
-Given orally so blood concentration with rise and fall slowly vs crash and rush of injective heroin
What happens after methadone have stabilised withdrawal symptoms?
Patient gradually lowers their dosage via detoxification until they can abstained from it
Why is methadone given orally?
-Given orally so blood concentration with rise and fall slowly vs crash and rush of injective heroin
What is the recommended dosage for methadone/
10-40mg per dosage
Interested by up to 10 mg daily until no signs of withdrawal are seen
What is the antagonist substance?
Naltrexone
Antagonist Naltrexone- what is this?
Used in opioid addictions
Used for addicts in recovery to prevent relapse unlike methadone that manages withdrawal symptoms
Antagonist Naltrexone- what biological action is taken?
Blocks dopamine receptor sites so dopamine can bind
Antagonist Naltrexone- what effect does this have on feelings produced by drugs?
No pleasurable feeling so not rewarding
Antagonist Naltrexone- who is this given to?
People who can relapse
Antagonist Naltrexone- How is this given?
Liquid and tablets