The Daily Differential — Tuesday, April 21, 2026

2 of 5

Sedatives / Hypnotic Toxicity and Poisoning

Sedative-hypnotic overdoses are common, often mixed with alcohol or opioids, and range from benign somnolence to life-threatening respiratory depression....

At the Bedside

Common agents
Benzodiazepines, barbiturates, Z-drugs, chloral hydrate, many prescription sleep aids, and often co-ingested ethanol/opioids.
Typical exam
CNS depression, slurred speech, ataxia, nystagmus, hypoventilation in severe cases.
Benzodiazepines alone rarely cause profound respiratory failure; if the patient is deeply obtunded, suspect co-ingestion.
Workup
Fingerstick glucose first.
EKG, pulse oximetry, capnography if available.
BMP, acetaminophen/salicylate levels, ethanol level, pregnancy test if relevant.
Consider CT head only if trauma, focal deficits, or atypical course.
Management
Airway, breathing, circulation first; oxygen and ventilatory support as needed.
Most isolated benzodiazepine overdoses: supportive care and observation.
Barbiturate toxicity can be more severe: may cause hypotension, hypothermia, coma.
Consider activated charcoal if early and airway protected.
Disposition
Observe until ambulatory, awake, and protecting airway; medically clear when sober enough and no self-harm risk.
ICU for barbiturate overdose, persistent coma, or respiratory failure.
Flumazenil
Generally avoid in unknown overdoses, chronic benzodiazepine users, seizure disorders, or mixed ingestions due to seizure/dysrhythmia risk.
May be considered only in very select iatrogenic/isolated benzodiazepine cases with expert guidance.

Classic Presentation

A 31-year-old is found somnolent after “sleeping pills” and wine. He is arousable to pain, has slurred speech and mild ataxia, normal pupils, and a normal glucose. Capnography shows mild hypoventilation, but he improves with oxygen and observation. Because the ingestion is mixed/uncertain, flumazenil is avoided, and serial reassessment confirms steady recovery.

Study Directive

Build a mental map of sedative toxidromes: isolated benzo vs mixed overdose vs barbiturate.
Memorize the one-line flumazenil contraindications: chronic use, seizure disorder, mixed/unknown overdose.
Practice the disposition question: “Who can be observed, who needs ICU, and who needs airway management?”
Review capnography and airway criteria for toxicology patients.
Do 3 quick cases distinguishing benzo intoxication from opioid and ethanol intoxication.

Key Medications

Naloxone if opioid co-toxicity suspected: start 0.04–0.4 mg IV, titrate; may require higher doses or infusion.
Flumazenil: 0.2 mg IV over 15 seconds, then 0.1–0.2 mg every 1 minute to effect; typical max 1 mg initially. Use only with great caution and ideally toxicology input.
Activated charcoal: 1 g/kg PO/NG, usual adult 50–100 g if airway protected.
Dextrose if hypoglycemic: 25 g IV (e.g., D50 50 mL), then recheck.
Thiamine 100 mg IV if malnourished/alcohol use disorder and concern for deficiency.
Note: Dosing of flumazenil and its role vary; if unsure, consult a toxicologist or reference.

High-Yield Pearls

Benzodiazepines alone usually don’t kill by themselves; dangerous cases often involve co-ingestants.
Flumazenil can unmask seizures or withdrawal in dependent patients.
Barbiturates are more likely than benzodiazepines to cause profound coma and hypotension.

Board Question

Which patient is the best candidate for flumazenil?

AA chronic benzodiazepine user with unknown pill ingestion and seizures in the past
BA patient with isolated iatrogenic oversedation after a procedural benzodiazepine dose
CA patient with mixed overdose including tricyclic antidepressants
DA patient with coma and respiratory depression after alcohol and diazepam

Reveal answer

Correct: B

Flumazenil is reserved for select, clearly isolated benzodiazepine toxicity, such as iatrogenic oversedation, because it can precipitate seizures and withdrawal. It should be avoided in chronic users, mixed overdoses, and seizure-prone patients.

3 of 5

Sympathomimetic Toxicity and Poisoning

Sympathomimetic toxicity can progress rapidly to hyperthermia, rhabdomyolysis, seizures, stroke, and death. Recognition matters because treatment is...

At the Bedside

Common causes
Cocaine, amphetamines/methamphetamine, MDMA, synthetic cathinones, ephedrine, caffeine, and some prescription stimulants.
Classic findings
Agitation, anxiety, mydriasis, tachycardia, hypertension, diaphoresis, hyperthermia, chest pain, tremor, psychosis.
Severe toxicity: seizures, ischemia, arrhythmia, rhabdo, DIC, renal failure, metabolic acidosis.
Workup
Fingerstick glucose.
EKG, troponin if chest pain or high-risk stimulant exposure.
BMP/creatinine, CK, lactate, urine or serum testing only if it changes management (routine tox screens often have limited utility).
Temperature monitoring; evaluate for hyperthermia aggressively.
Management
First-line: benzodiazepines to reduce agitation, sympathetic surge, and seizure risk.
Active cooling for hyperthermia: remove clothing, ice packs, mist/fan, chilled IV fluids as adjuncts; severe cases may need paralysis/intubation for refractory hyperthermia.
IV fluids for dehydration/rhabdo; treat complications.
Chest pain: evaluate for ACS, aortic pathology, vasospasm.
Blood pressure management
Benzodiazepines first.
If persistent severe hypertension: consider vasodilators or calcium channel blockers depending on the scenario.
Pure beta-blockade is generally avoided in acute cocaine toxicity because of concern for unopposed alpha vasoconstriction; local practice varies for combined alpha/beta agents, but first-line remains sedation and vasodilation.
Disposition
Discharge only after normalization of mental status, vitals, and temperature, and exclusion of dangerous complications.
ICU for hyperthermia, severe agitation requiring heavy sedation, rhabdo, seizures, or end-organ injury.

Classic Presentation

A 28-year-old man arrives combative, sweaty, tachycardic, hypertensive, and with a temperature of 40.1°C after using “a bunch of meth” and dancing all night. He has dilated pupils, CK is markedly elevated, and he is becoming confused. He receives repeated benzodiazepines, aggressive cooling, and IV fluids; after sedation he stabilizes, but is admitted because of hyperthermia and rhabdomyolysis.

Study Directive

Memorize the sympathomimetic toxidrome: diaphoresis, mydriasis, agitation, tachycardia, hypertension, hyperthermia.
Practice a cooling algorithm from memory: remove clothes → ice/fan → benzos → intubation/paralysis if refractory.
Review stimulant chest pain management and the reasoning behind avoiding pure beta-blockade in cocaine toxicity.
Write out the top 5 complications: hyperthermia, rhabdo, seizure, ACS, stroke.
Do one timed board question on agitated delirium and one on cocaine chest pain.

Key Medications

Lorazepam: 1–2 mg IV every 5–10 min titrated to calm/sedate; higher doses often needed.
Diazepam: 5–10 mg IV every 5–10 min if preferred/available.
Midazolam: 2–5 mg IV/IM, repeat as needed; useful if IV access limited.
Active cooling: no drug dose; start immediately for temp elevation.
Nitroglycerin for stimulant-associated ischemic chest pain/hypertension: 0.4 mg SL q5 min x3 or IV infusion per protocol.
Nicardipine for severe hypertension when needed: titrate IV infusion per institutional protocol.
Note: BP management varies by toxidrome and comorbidity; consult toxicology for refractory cases.

High-Yield Pearls

Hyperthermia is a medical emergency in stimulant toxicity; it predicts bad outcomes.
Benzodiazepines treat both agitation and hypertension by reducing central sympathetic outflow.
Do not chase the urine drug screen; treat the syndrome and complications.

Board Question

A patient with cocaine intoxication is severely agitated, hypertensive, and tachycardic. Which of the following is the best initial therapy?

AImmediate haloperidol monotherapy
BIV benzodiazepines
CPropranolol
DFlumazenil

Reveal answer

Correct: B

Benzodiazepines are first-line because they calm agitation and blunt the adrenergic surge. Haloperidol may be adjunctive in selected cases, propranolol is generally avoided in acute cocaine toxicity, and flumazenil is irrelevant.

4 of 5

Toxic Alcohol Poisoning

Methanol, ethylene glycol, and related alcohols cause delayed but devastating organ injury, and patients can look deceptively well early on. Early...

At the Bedside

Suspect toxic alcohols when there is unexplained anion gap metabolic acidosis, osmolar gap, visual symptoms, renal injury, or history of antifreeze/solvent ingestion.
Clinical clues
Methanol: visual symptoms (“snowfield” vision), headache, abdominal pain, acidosis.
Ethylene glycol: inebriation, nausea/vomiting, flank pain, AKI, hypocalcemia, calcium oxalate crystals.
Isopropanol: ketosis without acidosis; CNS depression, hemorrhagic gastritis.
Workup
BMP, ABG/VBG, lactate, measured serum osmolality, osmolar gap, serum ketones, ethanol level, creatinine, calcium, urinalysis.
EKG; consider head/eye exam if methanol suspected.
Serial labs are useful because gaps change over time.
Initial management
Fomepizole is the antidote of choice for methanol and ethylene glycol.
Give thiamine and pyridoxine in suspected ethylene glycol poisoning.
Correct acidosis with bicarbonate as needed.
Consult toxicology and nephrology early.
Hemodialysis
Indicated for severe acidosis, end-organ injury, renal failure, visual symptoms, large ingestions, or worsening despite antidote/support.
Thresholds vary by agent, level, and clinical status; use local protocol/toxicology guidance.
Disposition
Most confirmed/suspected cases need ICU or step-down with frequent lab reassessment.

Classic Presentation

A 42-year-old man is brought in after drinking “engine coolant” during a dispute. He is initially intoxicated but later develops tachypnea and blurry vision. Labs show a high anion gap metabolic acidosis and elevated osmolar gap; urinalysis reveals calcium oxalate crystals. He is started on fomepizole, bicarbonate, thiamine/pyridoxine, and undergoes emergent hemodialysis.

Study Directive

Draw the metabolic pathways for methanol and ethylene glycol and mark where fomepizole acts.
Memorize the three key gap patterns: osmolar gap early, anion gap later, ketosis without acidosis for isopropanol.
Practice a dialysis decision checklist: severe acidosis, visual symptoms, renal failure, refractory clinical worsening.
Review your local fomepizole and dialysis protocol.
Do 5 practice cases identifying which alcohol is most likely from the lab pattern.

Key Medications

Fomepizole: 15 mg/kg IV loading dose, then 10 mg/kg IV q12h x4 doses, then 15 mg/kg IV q12h thereafter; dose adjustment is needed during hemodialysis and protocols vary—verify with reference.
Thiamine: 100 mg IV.
Pyridoxine (vitamin B6): 50 mg IV; some protocols use higher doses—check reference if treating large ethylene glycol ingestions.
Sodium bicarbonate: for significant acidosis, per acid-base status and protocol.
Activated charcoal: generally limited utility unless very early and specific scenario; consult toxicology.
Note: Fomepizole dosing changes with dialysis and may vary by institution.

High-Yield Pearls

Anion gap rises later as toxic metabolites accumulate; osmolar gap may be highest early.
Methanol causes visual toxicity; ethylene glycol causes renal toxicity and oxalate crystals.
Isopropanol = ketosis without acidosis is the classic distinguishing clue.

Board Question

A patient presents with a high anion gap metabolic acidosis and elevated osmolar gap after suspected antifreeze ingestion. Which therapy most directly prevents further toxic metabolite formation?

AActivated charcoal
BFomepizole
CNaloxone
DFlumazenil

Reveal answer

Correct: B

Fomepizole inhibits alcohol dehydrogenase, preventing formation of toxic metabolites from methanol and ethylene glycol. Activated charcoal is often not helpful, and naloxone/flumazenil do not address toxic alcohol metabolism.

5 of 5

Acute Liver Failure

Acute liver failure is a high-mortality emergency requiring rapid recognition, transplantation evaluation, and targeted management of cerebral edema,...

At the Bedside

Definition
Acute liver injury with encephalopathy and INR ≥ 1.5 in a patient without preexisting cirrhosis, typically within weeks of symptom onset.
Key causes
Acetaminophen, viral hepatitis, ischemic hepatitis, autoimmune hepatitis, Wilson disease, toxins, pregnancy-related causes, vascular causes, and indeterminate.
ED priorities
ABCs, mental status, bedside glucose.
Treat hypoglycemia immediately.
Assess for encephalopathy grade, bleeding, infection, shock, and cerebral edema.
Workup
CMP, AST/ALT, bilirubin, INR/PTT, fibrinogen, CBC, ammonia, lactate, VBG/ABG, creatinine, glucose.
Acetaminophen level in all acute liver failure presentations, even if history is unclear.
Hepatitis serologies, autoimmune markers, pregnancy test when indicated, ceruloplasmin/hemolysis evaluation if Wilson disease suspected.
RUQ ultrasound with Doppler if vascular/biliary pathology suspected.
Blood cultures if infection possible.
Management
N-acetylcysteine (NAC) for suspected or confirmed acetaminophen toxicity, and often empirically in undifferentiated acute liver failure because of benefit and safety.
ICU care; early hepatology and transplant center consultation.
Manage encephalopathy with airway protection if needed; lactulose is often used though acute liver failure management is broader than cirrhosis.
Avoid unnecessary sedatives; maintain euvolemia and normoglycemia.
Monitor for cerebral edema: worsening mental status, hypertension/bradycardia, pupillary changes.
Disposition
Many patients require transfer to a liver transplant center if not already at one.
Coagulopathy alone is not the endpoint; prognosis depends on mental status, INR, creatinine, lactate, and etiology.

Classic Presentation

A 19-year-old woman presents 24 hours after a large acetaminophen ingestion with nausea, right upper quadrant pain, and confusion. Her AST and ALT are in the thousands, INR is 3.2, and glucose is low. She is started on IV NAC, glucose is corrected, and hepatology is contacted urgently for transplant evaluation and ICU admission.

Study Directive

Memorize the definition of acute liver failure and the major causes.
Practice a 30-second transplant referral summary: etiology, INR, glucose, creatinine, lactate, mental status, and timeline.
Write out the IV NAC regimen from memory and know when it may need extension.
Review indicators of poor prognosis and when to escalate to a transplant center.
Do one case on Wilson disease vs acetaminophen toxicity in acute liver failure.

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Mechanism Pearl of the Day: Several of today’s toxidromes hinge on whether a toxin pushes the body toward acidemia or sympathetic overdrive: salicylates and toxic alcohols create dangerous acid-base shifts that increase tissue penetration and organ injury, while stimulants and sedatives threaten by overwhelming physiologic reserve through autonomic excess or CNS/respiratory depression.

Key Medications

N-acetylcysteine (IV):
Common 21-hour regimen: 150 mg/kg over 1 hr, then 50 mg/kg over 4 hr, then 100 mg/kg over 16 hr.
Many centers extend or repeat NAC until liver injury improves; verify institutional protocol.
N-acetylcysteine (PO): 140 mg/kg load, then 70 mg/kg every 4 hr x17 doses if used.
Dextrose: 25 g IV for hypoglycemia, repeat as needed.
Lactulose: 20–30 g PO/NG, titrated to 2–3 soft stools/day; use with caution and based on encephalopathy management plan.
Vitamin K: 5–10 mg IV/PO if deficiency possible; does not fix true synthetic failure but may help if deficient.
Note: NAC duration often depends on transaminases, INR, creatinine, mental status, and acetaminophen detectability.

High-Yield Pearls

Acute liver failure is defined by encephalopathy plus INR elevation, not by transaminase level alone.
Acetaminophen level should be checked in all cases—history is often unreliable.
Hypoglycemia and cerebral edema are immediate threats and can kill before transplant becomes possible.

Board Question

Which of the following is the most appropriate empiric therapy for an undifferentiated patient with acute liver failure and encephalopathy?

AN-acetylcysteine
BFlumazenil
CActivated charcoal only
DLactated Ringer’s infusion as definitive therapy

Reveal answer

Correct: A

N-acetylcysteine is recommended for suspected acetaminophen toxicity and is commonly given empirically in undifferentiated acute liver failure because of safety and potential benefit. Flumazenil is not indicated, charcoal is not definitive once liver failure is present, and fluids alone do not treat the underlying hepatic injury.

TheDaily Differential

Salicylate Poisoning

At the Bedside

Study Directive

More in Today's Issue

Sedatives / Hypnotic Toxicity and Poisoning

At the Bedside

Study Directive

Key Medications

High-Yield Pearls

Sympathomimetic Toxicity and Poisoning

At the Bedside

Study Directive

Key Medications

High-Yield Pearls

Toxic Alcohol Poisoning

At the Bedside

Study Directive

Key Medications

High-Yield Pearls

Acute Liver Failure

At the Bedside

Study Directive

Key Medications

High-Yield Pearls

Journal Watch

Clinical Conundrum: What Is the Role of TXA in Dysfunctional Uterine Bleeding?

Podcast Pick

Case of the Day