Alcohol used disorder Flashcards
(47 cards)
Which receptor is activated by EtOH?
GABA receptors.
How does alcohol acutely affect NMDA and GABA receptors?
Alcohol is a GABA-A agonist (causing sedation) and an NMDA receptor antagonist (reducing excitatory transmission). This leads to CNS depression.
What are the acute features of intoxication?
- Stupor
- Overall central nervous system depression
- Slurred speech
- Ataxia
- Emotional lability
- Slowed respirations
- Coma
What is alcohol use disorder (AUD)?
A maladaptive pattern of alcohol use causing functional impairment and distress, classified by DSM-5 criteria.
What are the risk factors for alcohol use disorder?
- Family history (multifactorial genetic basis)
- Psychiatric disorders
- Early exposure to alcohol
- Social factors
How is alcohol use disorder diagnosed according to DSM-5?
At least 2 of 11 criteria within 12 months, including failed obligations, hazardous use, tolerance, withdrawal, cravings, and inability to cut back.
Why do chronic alcohol users develop tolerance?
With chronic use, NMDA receptors are upregulated (to compensate for inhibition), and GABA-A receptors are downregulated, requiring more alcohol for the same effect.
How does chronic alcohol use affect NMDA and GABA receptors?
Chronic alcohol use upregulates NMDA receptors and downregulates GABA-A receptors. This leads to withdrawal symptoms when alcohol is stopped due to excessive NMDA excitation and decreased GABA inhibition.
What happens when chronic alcohol use is suddenly stopped?
The brain is left with excess NMDA activity (excitotoxicity) and low GABA function, causing symptoms like agitation, tremors, seizures, and hallucinations.
What are the gastrointestinal complications of chronic alcohol use?
Gastritis, hepatitis, cirrhosis, pancreatitis, increased risk of esophageal and oropharyngeal cancers.
What are the cardiovascular complications of chronic alcohol use?
Dilated cardiomyopathy, hypertension, and arrhythmias like atrial fibrillation.
What are the neurological complications of chronic alcohol use?
Peripheral neuropathy, cerebellar degeneration, Wernicke-Korsakoff syndrome.
What causes Wernicke’s encephalopathy?
Thiamine deficiency, often precipitated by glucose administration without prior thiamine replacement.
What are the classic triad symptoms of Wernicke’s encephalopathy?
Nystagmus, ophthalmoplegia, ataxia, plus confusion.
What is Korsakoff syndrome?
An irreversible amnestic disorder with confabulation and apathy due to untreated Wernicke’s encephalopathy.
What is the treatment for Wernicke-Korsakoff syndrome?
IV thiamine before glucose administration.
What is the primary cause of autonomic instability in alcohol withdrawal?
Unopposed increased NMDA receptor activity leads to increased sympathetic output, causing hypertension, tachycardia, and diaphoresis.
What is the timeline of alcohol withdrawal symptoms?
6-24 hours: diaphoresis, palpitations, insomnia, tremors, anxiety, GI upset.
12-48 hours: seizures, hallucinations (visual or tactile), stable vitals.
48-96 hours: delirium tremens (DTs) indicated by agitation, hallucinations, hypertension, fever, death.
What is the mechanism of alcohol withdrawal?
Increased NMDA receptor activity and decreased GABAergic inhibition due to chronic alcohol use and sudden cessation.
Why does alcohol withdrawal cause seizures?
Chronic alcohol use suppresses NMDA receptor activity and enhances GABA-A function. When alcohol is abruptly stopped, NMDA receptors become overactive, leading to excitotoxicity and seizures.
What is the first-line treatment for alcohol withdrawal?
Benzodiazepines (e.g., lorazepam, diazepam, chlordiazepoxide) to enhance GABA-A receptor activity.
How does benzodiazepine treatment help in alcohol withdrawal?
Benzodiazepines enhance GABA-A receptor activity, counteracting the excitatory NMDA overactivity and preventing seizures and delirium tremens (DTs).
Which benzodiazepines are preferred in alcohol withdrawal?
Long-acting: diazepam, chlordiazepoxide
Short-acting for liver disease: lorazepam, oxazepam, temazepam (LOT drugs).
Which benzodiazepines is used for patients with liver failure?
lorazepam