One hour after undergoing an uncomplicated laparoscopic appendectomy, a 22-year-old man develops agitation and restlessness. He also has tremors, diffuse sweating, headache, and nausea with dry heaves. One liter of lactated ringer's was administered during the surgery and he had a blood loss of approximately 100 mL. His urine output was 100 mL. His pain has been controlled with intravenous morphine. He was admitted to the hospital 3 days ago and has not eaten in 18 hours. He has no history of serious illness. He is a junior in college. His mother has Hashimoto's thyroiditis. He has experimented with intravenous illicit drugs. He drinks 3 beers and 2 glasses of whiskey daily during the week and more on the weekends with his fraternity. He appears anxious. His temperature is 37.4°C (99.3°F), pulse is 120/min, respirations are 19/min, and blood pressure is 142/90 mm Hg. He is alert and fully oriented but keeps asking if his father, who is not present, can leave the room. Mucous membranes are moist and the skin is warm. Cardiac examination shows tachycardia and regular rhythm. The lungs are clear to auscultation. His abdomen has three port sites with clean and dry bandages. His hands tremble when his arms are extended with fingers spread apart. Which of the following is the most appropriate next step in management?

Administer intravenous lorazepam

Administer 5% dextrose in 1/2 normal saline

Administer intravenous naloxone

Administer intravenous propranolol

Administer intravenous dexamethasone

A 42-year-old homeless man is brought to the emergency room after he was found unconscious in a park. He has alcohol on his breath and is known to have a history of chronic alcoholism. A noncontrast CT scan of the head is normal. The patient is treated for acute alcohol intoxication and admitted to the hospital. The next day, the patient demands to be released. His vital signs are a pulse 120/min, a respiratory rate 22/min, and blood pressure 136/88 mm Hg. On physical examination, the patient is confused, agitated, and sweating profusely, particularly from his palms. Generalized pallor is present. What is the mechanism of action of the drug recommended to treat this patient’s most likely condition?

It increases the frequency of GABA-gated chloride channel opening.

It decreases the duration of GABA-gated chloride channel opening.

It increases the duration of GABA-gated chloride channel opening.

It activates the GABA receptors by binding at the GABA binding site.

It decreases the frequency of GABA-gated chloride channel opening.

A 26-year-old man with a history of alcoholism presents to the emergency department with nausea, vomiting, and right upper quadrant pain. Serum studies show AST and ALT levels >5000 U/L. A suicide note is found in the patient's pocket. The most appropriate initial treatment for this patient has which of the following mechanisms of action?

Competitive inhibitor of alcohol dehydrogenase

GABA receptor competitive antagonist

A 62-year-old man is referred to a gastroenterologist because of difficulty swallowing for the past 5 months. He has difficulty swallowing both solid and liquid foods, but there is no associated pain. He denies any shortness of breath or swelling in his legs. He immigrated from South America 10 years ago. He is a non-smoker and does not drink alcohol. His physical examination is unremarkable. A barium swallow study was ordered and the result is given below. Esophageal manometry confirms the diagnosis. What is the most likely underlying cause of this patient’s condition?

Pharyngoesophageal diverticulum

Gastroesophageal reflux disease

Squamous cell carcinoma of the esophagus

A mother presents to the family physician with her 16-year-old son. She explains, "There's something wrong with him doc. His grades are getting worse, he's cutting class, he's gaining weight, and his eyes are often bloodshot." Upon interviewing the patient apart from his mother, he seems withdrawn and angry at times when probed about his social history. The patient denies abuse and sexual history. What initial test should be sent to rule out the most likely culprit of this patient's behavior?

Sexually transmitted infection (STI) testing

Alcohol use disorder — USMLE Lesson

Diagnosis & Screening - Spotting the Signs

Screening Tools: CAGE questionnaire (quick), AUDIT-C (more sensitive).
DSM-5 Criteria: Problematic pattern of use with impairment, requiring ≥2 of 11 criteria in 12 months.
- Categories: Impaired control, social impairment, risky use, and pharmacological (tolerance/withdrawal).
Biomarkers:
- ↑ GGT (gamma-glutamyl transferase) - most sensitive marker.
- ↑ AST:ALT ratio (typically >2:1).
- ↑ MCV (macrocytosis).

⭐ An AST:ALT ratio >2 is highly suggestive of alcoholic hepatitis.

DSM-5 Categories of SUD Symptoms

Acute Intoxication - The Tipsy Turmoil

Pathophysiology: Potentiates GABA-A receptors (inhibitory) & inhibits NMDA receptors (excitatory), causing widespread CNS depression.
Clinical Features:
- Slurred speech, ataxia, incoordination, nystagmus.
- Disinhibition, impaired judgment, blackouts.
Diagnosis: Clinical; serum ethanol level correlates poorly with impairment due to tolerance.
Management: Supportive care, monitor vitals and glucose.

⭐ In suspected chronic alcohol use, always give thiamine before glucose to prevent precipitating Wernicke-Korsakoff syndrome.

Alcohol Withdrawal - The Shakes & Quakes

Pathophysiology: Chronic EtOH use → ↓ GABAergic tone & ↑ NMDA receptor activity. Cessation causes CNS hyperexcitation.

Alcohol Withdrawal Symptoms: Mild to Severe Progression

Management:
- Benzodiazepines (Chlordiazepoxide, Diazepam, Lorazepam) guided by CIWA-Ar scale.
- Give Thiamine (B1) before glucose to prevent Wernicke's encephalopathy.

⭐ In liver failure, use LOT: Lorazepam, Oxazepam, Temazepam, as they are metabolized outside the liver.

Chronic Complications - The Body's Toll

Neurologic: Wernicke-Korsakoff syndrome (thiamine deficiency), cerebellar degeneration (ataxia), peripheral neuropathy.
Cardiovascular: Dilated cardiomyopathy, hypertension, atrial fibrillation.
Gastrointestinal:
- Liver: Steatosis → Alcoholic Hepatitis → Cirrhosis
- Pancreatitis (acute & chronic)
- Gastritis, Mallory-Weiss tears
Hematologic: Macrocytosis (↑ MCV), thrombocytopenia.
Endocrine: Gynecomastia, testicular atrophy.

Healthy vs. Cirrhotic Liver Gross Specimen

⭐ Wernicke's encephalopathy presents with a classic triad: Confusion, Ophthalmoplegia (e.g., nystagmus), and Ataxia (mnemonic: COAt). Always give thiamine before glucose to prevent precipitating the syndrome.

Management - The Recovery Roadmap

Pharmacotherapy is key to preventing relapse.
- Naltrexone: ↓ cravings & rewarding effects. Oral or long-acting injection.
- Acamprosate: Modulates glutamate, good for maintaining abstinence. Requires 3x/day dosing.
- Disulfiram: Aversive agent. Causes nausea/vomiting with alcohol. Requires high motivation.

⭐ Naltrexone is contraindicated in patients taking opioids (can precipitate withdrawal) and those with acute hepatitis or liver failure.

High‑Yield Points - ⚡ Biggest Takeaways

CAGE questionnaire is the key screening tool.

Withdrawal is life-threatening; it starts with tremors and can progress to seizures, hallucinosis, and delirium tremens (DTs).

Treat acute withdrawal with benzodiazepines (e.g., lorazepam).

Maintenance therapy includes naltrexone (reduces cravings) and acamprosate.

Disulfiram creates an aversive reaction to alcohol.

Always give thiamine before glucose to prevent precipitating Wernicke-Korsakoff syndrome.

Lab findings often show ↑GGT, ↑AST > ↑ALT (2:1 ratio), and macrocytosis.

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