Drugs of abuse Flashcards
Function of dopamine pathway
Reward (motivation) Pleasure, euphoria Motor function Compulsion Preservation
Function of the serotonin pathway
Mood
Memory processing
Sleep
Cognition
What is the mess-limbic dopamine pathway
Cell bodies in ventral segmental area terminate in the nucleus accumbent
Which drugs increase dopamine release in the nucleus accumbent
Opiates Nicotine Amphetamine cocaine Ethanol Cannabis
Which drugs enhance serotonin
LSD
Ecstacy
What do drugs of abuse do to dopamine
What inhibits neural activity
Enhance release of dopamine fr9om VTA neurones
GABA
What is bromocriptine used for
Stopping breast milk production
Problems cause by not having right amount of prolactin
Treating non-cancerous tumours in the brain called prolactinomas
Treating Parkinson’s disease
What are are cautions with bromocriptine
What other drug should be cautioned that has these effects
It is a dopamine agonist which means that it can cause impulse control disorders and can cause behaviours such as addictive gambling, excessive eating or spending and abnormally high sex drive or an increase in sexual thoughts or feelings
ropirinole
What is the mode of action of opiates (e.g. heroin, morphine, codeine, fentanyl and methadone)
Agonists at G protein-coupled opioid receptors that lower neurotransmitter release in brain and periphery
Acute Effects of opiates
euphoria, tranquility, mitosis, drowsiness, itching, nausea
Chronic effects of opiates
Constipation, depression, insomnia, dependence, Dancer of HIV and hepatitis from injecting, poor nutrition
Is it okay for heavily dependent users of opioids to suddenly withdraw
No
Mode of action of cocaine
Prevents reuptake of dopamine.
What dependence can cocaine cause
Little tolerance
Little physical dependence
Strong psychological dependence
Mode of action of amphetamines
release monoamines from neural storage vesicles and block re-uptake transporters, causing increased synaptic DA, NA and 5HT
Physical effects of amphetamines
amphetamine psychosis, increased cardiovascular tone, raised blood pressure, tachycardia
Mode of action of cannabis
Inhibits wide range of neurotransmitter release in the brain and periphery via specific Gi protein coupled cannabinoid receptors
What are the concerns with chronic heavy use with cannabis
Psychosis
What kind of therapy is needed for opioid misuse
Methadone (agonist substitution) along with psycho-social support because without psycho social support it is not effective.
How is methadone (treatment for opioids) administered and what is its mode of action
Long acting synthetic opiate agonist
administered orally for sustained period at dose sufficient to prevent opiate withdrawal
Use of varenicline and mode of action
Smoking cessation (partial receptor agonist)
Use of buprenorphine and mode of action
(partial)receptor agonist Opioid cessation
What is an agonist treatment for opiate addiction and how is it taken
Naltrexone - patients must be detoxified and opiate free for several days before taking
What is used for alcohol dependent patients and what is its mode of action
Acamprosate- reduces alcohol consumption and reduces neural excitability that occurs during alcohol withdrawal
Naltrexone- Interferes with positive reinforcement and possibly alcohol conditioned cues. Possibly acts by blocking endogenous opioid dis-inhibition of GABA neurones in VTA thereby reducing firing of dopamine releasing neurones
