Motivated Behaviour: Addiction and the Drugs of Abuse Flashcards
What is the difference between drug abuse and drug misuse?
abuse = social dissproval, culture, dependence, neurophysiological influences misuse = wrong indication, wrong dose, too long
What are the physical symptoms of dependence?
- anxiety
- nausea and vomiting
- cramps
- tachycardia
- piloerection
- diarrhoea
What are the psychological symptoms of dependence?
- compulsive behaviour
- anxiety
What is the difference between physical and psychological dependence?
- one can overcome physical dependence quite quickly - 3-4 weeks
- psychological dependence never goes away –> more likely to become dependent again
What are the variables that make up the origins of dependence?
- drug variable
- degree of reward - user variable
- absorption/metabolism, genetics - environmental variable
- peer pressure
Describe how and why genetics is a factor in the origins of alcohol dependence
increased alcohol consumption
increased enzymes
increased conc needed to get reward
This is controlled by genetic factors
What is the difference between innate and acquired tolerance?
Innate - genetics Acquired - metabolic - behavioural (learning to behave normally while under the influence) - pharmacodynamic
Describe te pharmacodynamic tolerance of opiates
- opiates bind to receptor
- inhibit cAMP production
- cells respond by increasing adenylate cyclase
- need more opiate to have effect
- when opiates withdrawn –> too much cAMP
Give examples of opiates
What are the characteristics of opiates
- morphine - naturally derived from poppies
- heroin - synthetic version
- pethidine - synthetic, different metabolism, same receptors, used in childbirth
What is the mechanism of action of opiates?
- act of GABAergic receptors
- inhibit the receptors
- increase Dopamine
How is an opiate overdose treated?
naloxone
- very short half-life
- similar in structure but antagonist at receptor
- competitive inhibition
- need naloxone infusion as opiate long half life
What is the treatement for opiate dependence?
- need motivated patient
Methadone = opiate agonist, longer half life, dependence transferred onto methadone, little risk, not a good rush if you
What is caffeine an example of?
What are its withdrawal symptoms?
What is it’s mechanism of action?
- a stimulant
- withdrawal symptoms = lethargy, irritability, w/e headache
- PDE inhibitor –> increase cAMP, activates neurones, also acts as adenosine receptor antagonist –> blocks inhibitory effect
- promote neuronal activity
What is cocaine an example of?
What are some names for it?
What is its mechanism of action?
- a stimulant
- crack,
- inhibits catecholamines uptake, rewarding, tissue necrosis, withdrawal eased with TCA
- blocks dopamine reuptake –> reward
What is amphetamine an example of?
What is their mechanism of action?
What is an overdose treated with?
- Stimulant
- cause release of NA, block reuptake of NA
- overdose treated with neuroleptics (antischizophrenic drugs)
