Alcohol Flashcards
Ethanol: Behavior Effects
Sedative Hypnotic/CNS Depressant
Ethanol: Absorption
Rapid and distributes to all tissues (placental included). Slowed by previous food intake
Explain the Metabolism of Ethanol
Alcohol is metabolized by alcohol dehydrogenase (ADH) at levels <0.1%
Microsomal Ethanol Oxidizing System metabolizes at blood ethanol levels above 0.1%
What BAC level is considered the “danger zone”?
100-200 mg/dL
This is the level of social dysfunction (Excitement, decreased inhibitions, impaired motor function, slurred speech, ataxia)
EtOH Major Actions in CNS
Sedative effects
- Enhances the affinity for GABA at its receptor. Remember GABA is inhibitory
- Inhibit glutamate activation of glutamatergic NMDA receptors.
Additional EtOH effects in the CNS
- Chronic uses increases the synaptic concentrations of dopamine, serotonin, and endogenous opioids in nucleus accumbens and the VTA
- Enhances calcium-activated, voltage gated BK potassium channels
Treatment for Acute Intoxication
Maintain VS and prevent aspiration
Give “Banana Bag” and IV dextrose if Wernicke-Korsakoff is suspected
The Mechanism of Disulfiram
Inhibits acetaldehyde dehydrogenase, causing a buildup of acetaldehyde.
Acetaldehyde leasd to nausea, vomiting, headache, and hypotension.
Mechanism of Clonidine, Propanolol
- Clonidine activates alpha2 adrenergic receptors in CNS to decrease sympathetic outflow
- Propanolol blocks beta adrenergic receptors in CNS to decrease sympathetic outflow
Therapeutic Use of Clonidine, Propanolol
Used to treat mild alcohol withdrawal symptoms (anxiety, insomnia, tremors, muscle aches, sweating, cramping, arrhythmias)
Clinical Use of Diazepam
Severe alcohol withdrawal syndrome leading to convulsion
Mechanism of Action of Diazepam
Activates GABA-A receptors in CNS. Benzos act by increasing affinity of endogenous GABA to GABA-A receptor
Naltrexone: MOA
Inhibits mu opioid receptors in the VTA
This is anti-craving therapy used to prevent relapse in recovering alcoholics
Topiramate: MOA and Indication
MOA: enhances GABA-A receptor activity and inhibits excitatory glutamatergic receptor activity
Indication: anti-craving medication NOT for withdrawal symptoms
Fomepizole: Indication
Used for methanol and ethylene glycol poisioning
Fomepizole: MOA
Binds with ADH to prevent to metabolism of methanol and ethylene glycol to toxic metabolites
N-acetylcysteine (NAC)
Used to treat chronic alcoholics suspected of acetaminophen poisoning
Clinical Use of Naloxone
Suspect recovering alcoholic is abusing opioids; perform Narcan challenge test prior to treatment with naltrexone
Naloxone: MOA
Inhibits mu opiod receptors in VTA
Two Kinds of Tolerance
- Metabolic tolerance (pharmacokinetic)- induction of MEOS enzymes
- Functional tolerance (pharmacodynamic)- reduction of CNS sensitivity to ethanol due to adaptive changes in neurons
What BAC level is associated with respiratory depression and death?
> 500 mg/dL
How long does it take for ADH to metabolize a single drink (15 g ethanol)
1.5-2 hours
Liver Effects of Ethanol
Decreased gluconeogenesis, hypoglycemia, NAD depletion, fatty accumulation in the liver. Eventual hepatitis and cirrhosis
GI Effects of Ethanol
Inflammation, bleeding, scarring –> eventual absorption deficits
Endocrine Effects of Ethanol
Altered steroid metabolism (gynecomastia, testicular atrophy, salt retention)
Cardiovascular Effects of Ethanol
Anemia, Hypertension, Ventricular hypertrophy (increased risk for MI)
Neoplasia and Ethanol
Increased incidence of esophageal, mouth, breast, ovarian and colorectal cancer
Nervous System Effects of Ethanol
Peripheral Neuropathy
Wernicke-Korsakoff Syndrome
Associated with thiamine deficiency resulting in encephalopathy
Symptoms: ataxia, confusion, paralysis of extraocular muscles, memory loss; can progress to coma and death
Fetal Alcohol Syndrome
Intellectual disability, growth deficiencies, microcephaly, underdevelopment of the mid-face region
Alcohol Withdrawal Syndrome
Mild: anxiety, insomnia, tremors, agitation, muscle aches, sweating, cramping, N/V/D, arrhythmias
Severe: hallucinations, DTs, and seizures
