Cocaine and Amphetamines

1. THE 2-MINUTE PHYSIOLOGY (Rapid Pathophysiology)

• Catecholamine Surge: Cocaine and amphetamines exert profound sympathomimetic, vasoconstrictive, psychoactive, and local anesthetic properties. They drive a massive systemic catecholamine excess that hyper-stimulates both alpha- and beta-adrenergic receptors, leading to multiorgan toxicity.
• Cardiovascular Catastrophe: At the myocardial level, cocaine directly induces severe vasoconstriction in the coronary arteries, triggering ischemia, myocarditis, toxic cardiomyopathy (including Takotsubo), and acute coronary syndromes. It also creates catastrophic vascular shearing forces, predisposing the patient to aortic rupture and coronary artery dissection.
• The Cocaethylene Threat: When cocaine is co-ingested with ethanol, the liver forms cocaethylene, an active metabolite possessing a half-life 3 to 5 times longer than the parent compound, carrying a significantly higher risk of sudden cardiac death.
• Synthetic Amphetamines: Novel psychoactive substances (e.g., MDMA/ecstasy, "bath salts") combine classic stimulant effects with hallucinogenic and psychedelic properties, frequently producing longer-lasting and more intense systemic toxicity than traditional cocaine or amphetamines.

2. THE BEDSIDE ACTION PLAN (Rapid ER Management)

• Agitation & Sympathetic De-escalation: Intravenous benzodiazepines are the absolute first-line, key therapeutic intervention for sympathomimetic toxicity. They effectively blunt the central catecholamine drive, treating hypertension, tachycardia, and agitation. If agitation is severe and refractory to escalating benzodiazepine doses, ketamine, olanzapine, or butyrophenones are the preferred alternative adjuncts.
• Hemodynamic Control: If hypertension and chest pain persist despite generous benzodiazepine administration, short-acting antihypertensives such as phentolamine, nitroglycerin, nicardipine, or clevidipine are the required adjuncts.
• Hyperthermia Resuscitation: Worsening hyperthermia portends imminent death and must be treated aggressively. Reduce core body temperature rapidly utilizing external cooling, deep sedation, and, if necessary, endotracheal intubation with neuromuscular paralysis.
• Dysrhythmia Management: Toxic doses of cocaine or certain amphetamine derivatives (e.g., bupropion) block fast myocardial sodium channels, leading to wide-complex dysrhythmias. These must be treated immediately with intravenous sodium bicarbonate,.
• Body Packer Decontamination: Cocaine "body packers" who develop clinical toxicity (due to leaking packets) require emergent surgical intervention to limit bowel necrosis and life-threatening sequelae,.

3. THE DIAGNOSTIC GRID (Differential Diagnosis & Workup)

• The "Can't-Miss" Mimics:
• Anticholinergic Toxicity: Closely mimics the sympathomimetic toxidrome (tachycardia, delirium, mydriasis) but classically presents with dry, flushed skin rather than the profound diaphoresis seen with stimulants,.
• Alcohol/Sedative-Hypnotic Withdrawal: Can present with an identical clinical picture of severe catecholamine excess, delirium, and seizures,.
• CNS Catastrophes: Intracranial hemorrhage, ischemic stroke, and central nervous system infections (meningitis/encephalitis) frequently present with extreme agitation and altered mental status,.
• Hypoglycemia: A rapidly reversible metabolic mimic of altered mental status.
• Prioritized Diagnostic Workup:
• Bedside Capillary Glucose: Mandatory immediately upon arrival to rule out hypoglycemia.
• 12-Lead ECG & Cardiac Biomarkers: Required for patients presenting with chest pain, palpitations, or dyspnea to evaluate for acute ischemia or conduction abnormalities. Note that elevated troponin levels in a cocaine user are highly predictive of true angiographic coronary stenosis, not merely vasospasm,.
• Chemistry Panel & Creatine Kinase (CK): Essential for any patient with agitation or hyperthermia to evaluate for metabolic acidosis, acute renal failure, and rhabdomyolysis. Actively screen for hyponatremia, which frequently occurs with hallucinogenic amphetamines like MDMA,.
• Coagulation & Liver Function Tests: Indicated specifically if the patient is hyperthermic (>104°F or 40°C) to assess for end-organ failure.

4. THE VISUAL BOARD (ECG / POCUS / Imaging)

• The 12-Lead ECG: Scrutinize for QRS widening indicating lethal sodium channel blockade (requiring sodium bicarbonate), as well as ST-segment depressions or elevations signifying acute coronary syndrome,.
• Non-Contrast CT Brain: Mandatory for any intoxicated patient presenting with severe headache, focal neurologic complaints, or prolonged lethargy/coma to definitively rule out intracranial hemorrhage,,.
• Abdominal Radiography: If the history suggests drug smuggling, plain films may reveal multiple uniform radio-opaque foreign bodies in the GI tract indicative of a "body packer",.

5. THE SCORING MATRIX (Risk Stratification & Guidelines)

• Admission Criteria for Cocaine-Related Chest Pain: Patients must be admitted if they exhibit cardiogenic shock, congestive heart failure, dysrhythmias/conduction abnormalities, ECG changes, elevated myocardial enzymes, multiple risk factors for CAD, persistent chest pain or abnormal vital signs, preexisting CAD or stents, or if they require ongoing vasodilating pharmacotherapy,.
• Observation vs. Discharge: Patients presenting with straightforward adrenergic excess from cocaine who demonstrate complete resolution of toxicity, a clear sensorium, and no focal complaints or end-organ damage can be medically cleared for discharge from the ED. However, because amphetamines have a significantly longer duration of effect, these patients frequently require prolonged observation or hospital admission.

6. THE DANGER ZONE (Pitfalls & Critical Actions)

• The Beta-Blocker Trap: Pitfall: Administering a beta-blocker to control tachycardia in a stimulant-intoxicated patient. Critical Action: Beta-blockers are strictly contraindicated. They leave alpha-adrenergic receptors unopposed, which lethally exacerbates coronary vasoconstriction and hypertension.
• The Urine Screen Trap: Pitfall: Relying on a urine drug screen (UDS) to guide acute management. Critical Action: While a UDS accurately detects the cocaine metabolite benzoylecgonine for 3 to 7 days after last use, it rarely changes acute, symptom-directed ED resuscitation. Notably, therapeutic lidocaine does not cause a false-positive cocaine screen,,.
• The Contaminant Trap: Pitfall: Anchoring on the stimulant toxidrome when the clinical picture is incongruent. Critical Action: If the clinical presentation does not fit the history (e.g., the patient reports using cocaine but is hypoxic and somnolent), immediately suspect a lethal regional contaminant or an occult co-ingestant like opioids,.
• The Elevated Troponin Misattribution: Pitfall: Assuming a positive troponin in a young cocaine user is benign "cardiac strain" or transient spasm. Critical Action: Recognize that positive cardiac markers in this demographic are highly predictive of severe angiographic coronary stenosis requiring definitive ACS management.

7. MCQ MASTERCLASS (Written Exam Tips)

• Buzzwords: "Mydriasis, tachycardia, hypertension, agitation, and marked diaphoresis." Exam Answer: Sympathomimetic toxidrome. (If the stem describes dry skin, it is the anticholinergic toxidrome).
• Buzzwords: "Widened QRS interval following a massive cocaine ingestion." Exam Answer: Administer intravenous sodium bicarbonate to overcome sodium channel blockade,.
• Buzzwords: "Cocaine user presents with severe, tearing chest pain radiating to the back and asymmetric blood pressures." Exam Answer: Aortic dissection. Treat immediately with short-acting antihypertensives like clevidipine, nicardipine, or phentolamine (avoiding beta-blockers),.
• Distractor: An option suggests "administering propranolol to control the patient's heart rate." Correction: This is a lethal distractor; beta-blockers cause unopposed alpha-stimulation and worsen coronary ischemia.

8. THE BOARDROOM SCRIPT (OSCE & Oral Board Tips)

• The Initial Resuscitation: "The patient is presenting with a classic sympathomimetic toxidrome featuring extreme agitation, tachycardia, hypertension, mydriasis, and diaphoresis. My immediate priority is to de-escalate this life-threatening catecholamine surge, so I am ordering high-dose intravenous benzodiazepines. I will explicitly avoid all beta-blockers to prevent unopposed alpha-adrenergic coronary vasoconstriction."
• The Diagnostic Workup: "I am ordering a STAT bedside capillary glucose to rule out hypoglycemia. Because of the chest pain, I want an immediate 12-lead ECG to screen for acute ischemia or wide-complex dysrhythmias from sodium channel blockade, along with cardiac biomarkers. I will also order a chemistry panel and creatine kinase to evaluate for rhabdomyolysis and hyponatremia."
• Addressing Complications: "The patient's temperature is rising to 104°F. This worsening hyperthermia portends imminent decompensation. I am initiating rapid external cooling and preparing for endotracheal intubation with neuromuscular paralysis to halt muscular heat generation."