Drugs Of Abuse Flashcards
What is considered the main brain reward pathway
Dopamine Mesolimbic pathway VTA- nucleus accumbens
Also mesocortical
What drugs increase dopamine release
Opiates Nicotine Amphetamine Cocaine PCP Ethanol Cannabis Ecstasy Barbiturates Caffeine
What does Lsd and ecstasy increase the release of
Serotonin
Where do the serotonin pathways project to
Prefrontal cortex
Frontal Cortex
Hippocampus
what is serotonin involved in?
Mood
Memory processing
Sleep
Cognition
How do opiates work
Opioid receptors- G protein coupled receptors decrease AC decrease cAMP , open K channels and close Ca channels, reduces NT release and excitability
What are the general effects of opiates
Euphoria Analgesia Resp depression Sedation Itching Nausea
What are some chronic effects of opiates
Anhedonia Constipation Depression Insomnia Dependence Tolerance
On withdrawal from opiates what is the effect
Craving Restlessness Insomnia Muscle and bone pain Diarrhoea Vomiting Cold flashes and goose bumps Kicking movements
How does cocaine work?
Blocks Na+ channels
Increases catecholamine NT function by preventing reuptake (DA) most important
How do amphetamines work
Release monoamines from neural storage vesicles and blocks re-uptake transporters meaning there is increased
DA NA + 5HT in the synapse
What are the effects of amphetamines
Increased wakefulness Concentration Decreased fatigue and appetite Performance enhancing Euphoria Increase libido Self esteem and confidence Aggression Obsession Paranoia
What are some chronic effects of amphetamines
Increased cardiovascular tone and bp
Tachycardia
What is the action of ecstasy
Releases monoamine NTS
DA NA 5HT
What are the ‘negative’ effects of ecstasy
Interference with temp reg
Severe hyperthermia
Liver/kidney/CV system failure and death
What is the action of cannabis
THC mimics effects of small endogenous lipid messengers
Inhibits wide range of NT release via G protein coupled cannabinod receptors
How does cannabis stimulate appetite
Actions on feeding centres in the hypothalamus and possibly in the gut
What are some polling term effects of alcohol
Neuropathic Wernickes encephalopathy Myopathies Hepatotoxicities Haematological disorders Obesity Suicide
What drugs are used to substitute drugs of abuse
Methadone for heroine/opiate abuse - decreases opiate craving
What antagonist are used to reduce drug abuse
Naltrexone- in opiate
Mecamylamine- nicotine ( blocks reward)
Define dependence
Strong desire or sense of compulsion to take the substance
Difficulties in controlling use
Physical withdrawal state
Tolerance
Progressive neglect or other interests- more seeking taking and obtaining
Persistence despite detrimental effects
