L15: Addiction And Drugs Of Abuse Flashcards
What is drug abuse about
Social disapproval
What is a better term to use instead of drug abuse
Substance dependence
What is drug abuse not the same as
Drug misuse
What is drug misuse
A prescribed drug in the world indication, wrong dose or for too long
When do symptoms occur for someone who is dependent on a drug
When someone stops taking the drug
What are the categories of symptoms for substance dependence
Physical
Psychological
Name some examples of physical symptoms
Cramps
Tachycardia
Piloerection
Diarrhoea
Name same examples of psychological symptoms
Compulsive behaviour
Anxiety
What underlies dependence/ origins of dependence
Drug variable
User variable
Environmental variable
What is drug variable
The degree of reward mediated by dopamine in the mesolimbic dopamine pathway
What does the release of dopamine make the person feel
Reward
What is user variable
Each individual has a different variable based on how well a drug is absorbed and metabolised which is controlled by genetics to an extent
What is the environmental variable factors
Peer pressure
What are the 2 types of tolerance
1) Innate
2) acquired
What is tolerance
A reduced reaction of the drug due to repeated doses/uses
What is innate tolerance
Genetically controlled
If you are a fast metaboliser you are likely to be tolerant
What is acquired tolerance
If you are a regular consumer of the drug you are likely to build up tolerance
Also involves pharmacodynamic (mechanism of action) factors
Name examples of opiates
Heroin
Morphine
Pethidine
What pathway allow the rewarded feeling of opiates
Mesolimbic dopamine pathway
What receptors does opiates act on
Opiate receptors
Where are opiate receptors located
On GABA interneurones
What happens to the release of GABA when opiates bind to opiate receptors on GABA neurones
Release of GABA is inhibited
What type of neurotransmitters are GABA
Inhibitory
What does GABA usually inhibit the release of
Dopamine
If opiates inhibit the release of the inhibitory neurotransmitter of GABA what happens to the release of dopamine
Increases
Which receptor becomes activated to cause the release of GABA
GABAa receptors
What is the treatment for opiate overdose
Naloxone
What is naloxone
Opiate receptor antagonist
What is the issue with using naloxone
It has a short life therefore should be given continuously
What is the treatment for opiate dependence
Methodone
What is methodone
An opiate itself
How does methodone work
1) It becomes absorbed rapidly
2) has a longer half life so transition of physical symptoms is slower
3) dose is gradually reduced
How does opiate cause a release of GABA when they bind to opiate receptors on the GABA interneurones
1) activation of opiate receptors causes a decrease in adenyly cyclase
2) CAMP decreases
3) decrease in CAMP means less GABA is released
What are the 2 ways in which caffeine works
1) inhibits phosphodiesterase which breaks CAMP, therefore you increase CAMP and neuronal activity increases
OR
2) caffeine acts as antagonist of adenosine receptors to increase neuronal activity
What are the withdrawal symptoms of caffeine
Lethargy
Irritability
Weekend headaches
What is the mechanism of action of cocaine
1) Cocaine inhibits catecholamine (noradrenaline, adrenaline, dopamine) uptake
2) this gives a rewarding sensation
What are the side effects of cocaine
Tissue necrosis
What is the treatment for Cocaine
Tricyclic antidepressants
How does amphetamines cause a rewarding effect
Increases the release of catecholamine (noradrenaline, dopamine, adrenaline)
What is the treatment of overdose of amphetamine
Neuroleptic
What is a neuroleptic
Dopamine receptor antagonist
What is a derivative of amphetamine
Methylene-dioxymethamphetamine (MDMA)
What is the mechanism of action of MDMA
Causes the release of 5HT from neurones
What type of drug is cannabis
Lipid soluble
What receptors does cannabis work on
Cannabinoid receptors (SB1 and SB2)
What is SB1 associated with
Sedative effects
What is SB2 associated with
Immune system
You activate SB1 receptors at low doses what effect do you get
Euphoria
Uncontrollable laughter
Sharpened sensory awareness
At High doses of cannabis what do you get
Dream like state
Name 2 examples of sedatives
Alcohol
Benzodiazepines
What receptors does sedatives act at
GABAa receptors
What affect does sedatives have
Inhibit the neurone