Pharmacology of Ethanol Flashcards
1
Q
Absorption of alcohol
A
- Absorption: is rapid throughout entire GI tract; extremely rapid in small intestine.
- The more rapid the ingestion, the more rapid the absorption (dependent on concentration gradient).
- Presence of food slows absorption via delaying passage to small intestine, where extent and rate of absorption is greatest (a heavy meal can decrease peak concentration by 30%).
2
Q
Characteristics of alcohol distribution
A
- Distribution: Evenly distributed throughout all tissues and all fluids of the body.
- except: fat contains less water and less alcohol
- Distribution / equilibration is most rapid in areas of high blood flow (brain, liver, kidney, lung).
- Initial CNS effects within 5 min; peak effects within 15-60 min.
3
Q
Characteristics of metabolism of ethanol
A
- 98% liver - ADH and CYP2E1
- Small amount expired, urinated unchanged
- Zero order kinetics : 7-10 grams/hr
4
Q
Characteristis of antabuse (disulfiram)
A
- Antabuse is an aldehyde dehydrogenase inhibitor.
- Disulfiram administration ==> 5-10 fold increase in acetaldehyde levels
- ==> nausea/vomiting, respiratory and cardiovascular collapse, convulsions
5
Q
Role of NADH in alcohol metabolism
A
- For the oxidative reactions to continue the NADH that is formed must be oxidized to NAD.
- Mitochondrial oxidation of NADH to NAD is insufficient with the increased levels of NADH
- ==> disruptions in hepatic metabolic pathways
6
Q
Metabolic disruptions associated with alcohol abuse
A
- ↑ Blood lactate → acidosis, behavioral disturbances
- ↑ Mg2+ excretion → can lead to convulsions
- ↓ Uric acid excretion → may precipitate gout attacks
- ↑ Acetyl CoA → ↑ fatty acid synthesis combine with ↓ fat breakdown → fatty liver
- ↑ NADH → ↓ Krebs cycle activity, ↓ gluconeogenesis → hypoglycemia
7
Q
Effects of ethanol @ CNS
A
- depressant, sedative
- loss of inhibitions
- impaired reaction times, impaired judgement,
- emesis
- stupor
- respiratory depression
- analgesia
- anticonvulsive
- sleep effects
8
Q
Effects of ethanol on liver
A
- reversible damage → cirrhosis
- ascites
- varicosities
- increased bleeding time
9
Q
Effects of ethanol @ kidney
A
inhibits secretion of ADH → diuretic effect
10
Q
Effects of ethanol @ GI
A
- ulceration, bleeding
- pancreatitis
- decreased absorbtion of vitamins
11
Q
Effects of ethanol on fetus
A
- Prenatal or postnatal growth retardation
- AND altered morphogenesis (especially facial dysmorphology)
- AND CNS involvement (often mental retardation).
- 1st trimester = altered morphology
- 2nd = increased risk spontaneous miscarriage
- 3rd = decreased growth
12
Q
Tolerance development w/ethanol
A
- Development of tolerance (limited compared to opioids) and physical dependence.
- Cross tolerance with other CNS depressants such as anesthetics and benzodiazepines.
13
Q
Characteristics of early/minor w/drawal from ethanol
A
- onset: 0-48 hrs
- severity: mild - severe
- sx:
- mild agitation
- anxiety
- restlessness
- tremor
- anorexia
- insomnia
- seizures 6-48 hrs after onset of AWS
14
Q
Characteristics of late/major/DT w/drawal from ethanol
A
- onset: 24-150 hrs
- severity: potentially life-threatening
- sx:
- extreme overactivity
- disorientation
- confusion
- disordered sensory perception
- NO seizures
15
Q
Major drug interactions associate w/ethanol use
A
- Additive effects with CNS depressants
- Promotes GI bleeding if taken with aspirin
- Can alter liver’s processing of other drugs
- Disulfiram-like symptoms if taken with metronidazole or certain oral hypoglycemics.
