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Difficulty: EasySubstance-Related and Addictive Disorders

Police officers escort a 27-year-old man to the acute care triage desk after he was found highly agitated outside a nightclub. Witnesses reported seeing him ingest an unknown substance earlier in the evening. He is uncooperative, heavily diaphoretic, and clenching his jaw. Vital signs show a temperature of 37.7°C (99.9°F), pulse of 142/min, respirations of 24/min, and blood pressure of 188/110 mmHg. His pupils are dilated but reactive to light. Cardiopulmonary examination reveals rapid, regular heart sounds and clear lungs. He exhibits no focal motor deficits. A 12-lead electrocardiogram demonstrates sinus tachycardia. Which of the following is the best initial step in managing this patient's condition?

  1. A
    Administer intravenous propranolol
  2. B
    Transfer to the inpatient psychiatric ward for management of a brief psychotic disorder
  3. Administer intravenous lorazepamAnswer
  4. D
    Proceed immediately with a computed tomography scan of the head
  5. E
    Administer empiric intravenous ceftriaxone and vancomycin

Answer

Administer intravenous lorazepam
The correct answer is to administer intravenous lorazepam. This patient's presentation of severe agitation, diaphoresis, mydriasis, hypertension, and tachycardia following illicit substance ingestion is highly characteristic of a sympathomimetic toxidrome, most commonly due to cocaine. The first-line and most appropriate initial treatment for cocaine-induced psychomotor agitation and cardiovascular toxicity is a benzodiazepine (e.g., lorazepam or diazepam). Benzodiazepines enhance GABAergic inhibition, effectively decreasing central sympathetic outflow. This pharmacological action not only safely calms the patient but also lowers both blood pressure and heart rate, preventing severe complications such as myocardial ischemia or seizures.

Step-by-Step Solution

1
Identify the underlying clinical syndrome based on the patient's history and vital signs.
The combination of severe agitation, marked hypertension, tachycardia, diaphoresis, and mydriasis after nightclub substance use indicates a sympathomimetic toxidrome (most likely cocaine intoxication).
Establishing the correct toxidrome directly guides the immediate medical stabilization and pharmacological management.
2
Select the safest and most effective initial medication to reverse the sympathomimetic effects.
Intravenous lorazepam (a benzodiazepine) is identified as the first-line therapy.
Benzodiazepines reduce central sympathetic outflow, thereby alleviating agitation, lowering blood pressure, and reducing heart rate without risking unopposed alpha-adrenergic stimulation.

Key Concept

Benzodiazepines are the first-line pharmacological treatment for severe cocaine intoxication to control psychomotor agitation, hypertension, and tachycardia by decreasing central sympathetic outflow.
Estimated Time:1m 0s
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Topics

Substance-Related and Addictive Disorders

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