E1: Alcohol Flashcards
What is the difference between alcohol abuse and alcoholism?
Alcohol abuse is when the social life of an individual is impaired for at least 1 month as a results of alcohol, and alcoholism is the occurrence of tolerance and dependence as a result of prolonged abuse
What happens physiologically when you drink that may cause alcohol dependence?
Marked increase in the release of B endorphins in the dopamine reward pathway
At what rate is alcohol metabolized?
Alcohol follows zero order kinetics and the rate is independent of concentration
What enzyme metabolizes alcohol? What is it converted to?
Alcohol is metabolized by alcohol dehydrogenase to acetaldehyde. Acetaldehyde is then converted to acetate via aldehyde dehydrogenase
What two metabolism pathways are active with chronic alcohol consumption?
- Microsomal-ethanol oxidizing system (MEOS
- CYP2E1
What are the pharmacokinetics behind alcohol tolerance?
-Ethanol induces CYP2E1, so chronic users tend to have increased metabolism of alcohol
What are the pharmacodynamics behind alcohol tolerance?
- Down regulation of GABA, and upregulation of NMDA receptors.
- Severe withdrawal can occur due to pharmacodynamic tolerance
If you are tolerance to alcohol, what drugs are you probably tolerance to as well?
Benzodiazepines and barbiturates
What is the MOA of alcohol?
- A CNS depressant that binds to GABAa receptor to increase Cl influx and enhance inhibitor GABA transmission
- Increases DA in mesolimbic pathway
How does alcohol affect NMDA receptors?
It inhibits the effect of glutamate on the NMDA receptor and long term use causes up regulation of NMDA receptors
What is the major excitatory NT?
Glutamate
What is the major inhibitor neurotransmitter?
GABA
What causes anterograde amnesia when drinking too much alcohol?
Blockade of the NMDA receptors
What are the effects of alcohol on smooth muscle?
- Ethanol is a vasodilator
- may lead to hypothermia
- relaxes the uterus and has been used to prevent premature labor
What is the effect of alcohol on the kidneys?
-Deceases ADH thus produces a diuretic effect
What are the symptoms of acute alcohol toxicity?
- Emesis, stupor, coma, respiratory depression
- Metabolic and electrolyte disturbances
- Hypothermia
- Blood pressure and CO may be decreased
What causes hangovers?
Buildup of acetaldehyde, dehydration, and the beginning of withdrawal
If seizures occur with alcohol withdrawal, what should you treat with?
Lorazepam (Ativan)-Benzo
OR
Phenytoin- anticonvulsant
What are the long term effects of chronic alcohol abuse on the GI system?
- Gastritis and pancreatitis
- liver disease is most common (cirrhosis, alcoholic hepatitis, liver cancer)
- malnutrition
What is Wernicke-Korsakoff syndrome?
-paralysis of the eye muscles, ataxia, confusion, coma, and death due to thiamine deficiency in chronic alcohol abuse
What are the cardiovascular effects of long term alcohol abuse?
- Cardiomyopathy
- Arrhythmias
- HTN
What is the most effective modality for treating alcoholism?
A combination of pharmacological and psychosocial treatments
What kind of drug is Naltrexone?
Opioid receptor antagonist
What is the MOA of Naltrexone?
- Blocks the ability of alcohol to stimulate the reward pathway
- reduces cravings
What are the side effects of Naltrexone?
Large doses may cause liver damage, dont use in patients with liver damage
What kind of drug is Acamprosate?
Structural analog of GABA
What is the MOA of Acamprosate?
- Restores the normal balance of GABA and glutamate
- reduces cravings and likelihood of relapse
What is beneficial about Acamprosate when compared to Naltrexone?
Acamprosate is eliminated by the kidneys so it does not have liver toxicity
What is the MOA of Disulfiram (Antabuse)?
Inhibits aldehyde dehydrogenase so acetaldehyde builds up. This causes flushing, headache, nausea, confusion
-makes drinking unpleasant
What kind of drug is Topiramate?
Anticonvulsant
How does Topiramate help treat alcoholism?
-Decreases cravings and increase abstinence in recovering alcoholics, though mechanism is not understood
What are the symptoms of mild alcohol withdrawal?
-Anxiety, irritability, insomnia, nausea, tachycardia
What are the symptoms of severe alcohol withdrawal?
-Hallucinations, Delirium and tremors, seizures, arrhythmias, and hypotension
What are the pharmacologic treatment options of alcohol withdrawal?
1) diazepam or Chlordiazepoxide: prevents seizures and DTS, tapers symptoms
2) Lorazepam: treat seizures
3) Phentoin: secondary drug to treat seizures
