Drug Dependence Flashcards
Ethanol effects
Sedative
Hypnotic
Anaesthetic
Depression of CNS included some depression of inhibition so enhanced self confidence
Units of alcohol=
Volume (L) consumed x %abv
Absorption influenced by
Amount of food in stomach (especially high fat)
Peak blood alcohol conc occurs after
30-60 mins in absence of food
1-2 hours with food
1 unit of alcohol raises blood alcohol levels by approx
15mg/100ml
Alcohol metabolised at
15mg/100ml per hour, 0 order kinetics
volume of distribution of ethanol in body
0.7L/kg
Alcohol SE
Liver damage - fatty liver can lead to death of hepatocytes, fibrosis from scar tissue then cirrhosis
Foetal alcohol syndrome when high levels during pregnancy
Korsakoff’s
Anaemia
Alcohol aversion therapy
Disulfiram, used as aversion therapy by inhibiting aldehyde dehydrogenase, acetaldehyde is toxic and gives bad hangover effects
methanol metabolism problems
Produces formaldehyde then formic acid which can cause blindness in severe cases
Drug to reduce alcohol cravings
Acamprosate, NMDA antagonist to reduce craving
Naltrexone MOA
Opioid receptor antagonist reduces euphoria associated with alcohol to make it less appealing
Same mechanism for opioid dependence
BDZ MOA alcohol treatment
Potentiates GABA-A to treat alcohol withdrawal, not good if risk of continued alcohol use
More likely to produce dependence if
Rapid onset and elimination Increased dose Shorter duration of action Genetic predisposition e.g. in enzymes that metabolise Environmental cues encourage
physical dependence definition
Negative reinforcement of drug use, withdrawal effects
psychological dependence definition
Positive reinforcement, nice effects on mood/behaviour
Dopamine reward pathway between
Ventral tegmental area at top off brainstem to nucleus accumbens, relays to frontal region of cerebral cortex
Endogenous opioids
Enkephalins (help regulate nociception), endorphins
Opioid dependence treatment
Naltrexone blocks rewarding effects
Methadone MOA
Slow-acting opioid receptor agonist treats withdrawal and longer acting so to reduce addiction
Buprenorphine
Opioid receptor partial agonist
Nicotinic receptor role in nicotine addiction
activates nicotinic receptors in brain causing DA release in reward centre
Nicotine effects from nt release
DA - psychoactive effects
NA- increased attentiveness
GABA + endorphins- anxiolytic effects
Smoking cessation - nicotine replacement ±
Nicotine replacement relieves withdrawal symptoms with lower doses than tobacco smoking
