What first‑line emergency drugs should be stocked in the emergency department for the most common life‑threatening conditions such as anaphylaxis, cardiac arrest, acute coronary syndrome, severe asthma, status epilepticus, opioid overdose, hyperkalemia, severe bradycardia, massive pulmonary embolism, and beta‑blocker or calcium‑channel blocker overdose?

Emergency Department First-Line Medications for Life-Threatening Conditions

Every emergency department must stock 23 immediately-available antidotes and emergency medications, with an additional 14 available within 1 hour, to manage the most common life-threatening emergencies including cardiac arrest, anaphylaxis, opioid overdose, and toxicologic emergencies. 1

Cardiac Arrest

Core Resuscitation Drugs (Immediately Available)

• Epinephrine 1 mg IV/IO every 3–5 minutes is the mandatory first-line vasopressor during CPR, providing α-agonist vasoconstriction that improves coronary and cerebral perfusion pressure. 1, 2

• Amiodarone 300 mg IV/IO bolus followed by 150 mg for shock-refractory ventricular fibrillation or pulseless ventricular tachycardia after initial defibrillation attempts. 1, 2

• Lidocaine 1–1.5 mg/kg IV/IO bolus then 0.5–0.75 mg/kg may be used as an alternative antiarrhythmic if amiodarone is unavailable. 1, 2

• Sodium bicarbonate 50–150 mEq IV bolus is indicated specifically for hyperkalemia, tricyclic antidepressant overdose, or sodium channel blocker toxicity—not for routine cardiac arrest. 1, 2

• Calcium chloride 2000 mg IV or calcium gluconate 6000 mg IV is reserved for documented hypocalcemia, calcium channel blocker overdose, hypermagnesemia, or hyperkalemia—routine administration is harmful. 1, 2

Critical pitfall: Standard resuscitative measures (high-quality chest compressions at 100–120/min with depth ≥2 inches, early defibrillation at 120–200 J biphasic) take absolute priority over any medication administration; drugs must never delay these core interventions. 1, 2

Anaphylaxis

First-Line Treatment (Immediately Available)

• Intramuscular epinephrine 0.3–0.5 mg (0.3–0.5 mL of 1:1000 solution) into the anterolateral thigh is the single most critical intervention and must be administered immediately—before any other medication. 2, 3, 4, 5

• Repeat IM epinephrine every 5–15 minutes if bronchospasm, stridor, or hypotension persists after the initial dose. 2, 3, 4

• IV epinephrine 50 µg (0.5 mL of 1:10,000 solution) for severe cardiovascular collapse with profound hypotension unresponsive to IM dosing, repeated as needed with continuous cardiac monitoring. 2

• Rapid IV crystalloid bolus 1–2 L (or 5–10 mL/kg in children) of normal saline or lactated Ringer's to restore intravascular volume depleted by massive capillary leak. 2

Secondary Agents (After Epinephrine)

• Chlorphenamine 10 mg IV and hydrocortisone 200 mg IV may be given after epinephrine to prevent biphasic reactions, but these are not first-line and must never delay epinephrine. 2

• Salbutamol (albuterol) nebulized or IV infusion for persistent bronchospasm unresponsive to repeated epinephrine doses. 2

Critical pitfall: Antihistamines and corticosteroids have no role in the acute management of anaphylaxis and can create a dangerous false sense of security; epinephrine is the only medication that prevents death. 2, 3, 5, 6

Opioid Overdose with Respiratory Depression

Antidote Administration (Immediately Available)

• Naloxone 0.2–2 mg IV/IO/IM, titrated incrementally to restore adequate respiratory drive and protective airway reflexes—not to achieve full consciousness, which can precipitate severe withdrawal and agitation. 1, 2

• Intranasal naloxone 2–4 mg, repeated every 2–3 minutes if IV/IO access is unavailable or delayed. 1, 2

• Bag-mask ventilation with supplemental oxygen takes priority when naloxone cannot be administered immediately; airway support is more critical than antidote in the first 60 seconds. 2

• Maintenance naloxone infusion at two-thirds of the waking dose per hour to prevent recurrent respiratory depression from long-acting opioids (methadone, sustained-release formulations). 2

Critical pitfall: In cardiac arrest caused by suspected opioid overdose, high-quality CPR must be performed before naloxone administration; naloxone has no proven benefit in pulseless patients and must never delay chest compressions. 1, 2

Status Epilepticus

First-Line Anticonvulsants (Immediately Available)

• Lorazepam 0.1 mg/kg IV (maximum 4 mg per dose) or midazolam 0.2 mg/kg IM (maximum 10 mg) for initial seizure termination. 1

• Phenytoin 20 mg/kg IV at ≤50 mg/min or fosphenytoin 20 mg PE/kg IV at ≤150 mg PE/min for refractory seizures after benzodiazepines. 1

Severe Asthma / Status Asthmaticus

Bronchodilators and Anti-Inflammatory Agents (Immediately Available)

• Albuterol (salbutamol) 2.5–5 mg nebulized or 10–20 puffs via metered-dose inhaler with spacer, repeated every 20 minutes for the first hour. 1, 2

• Ipratropium bromide 0.5 mg nebulized combined with albuterol for severe exacerbations. 1

• Prednisolone 30–60 mg PO or methylprednisolone 125 mg IV within the first hour to prevent progression and reduce relapse rates. 1

• Magnesium sulfate 2 g IV over 20 minutes for life-threatening asthma (peak flow <50% predicted, silent chest, altered consciousness). 1

Critical pitfall: If the patient is unconscious or confused, call for immediate intubation assistance and provide uninterrupted high-flow oxygen; do not attempt intubation until the most experienced clinician (ideally an anesthesiologist) is present. 1

Acute Coronary Syndrome

Antiplatelet and Anticoagulation (Immediately Available)

• Aspirin 162–325 mg PO (chewed) immediately upon suspicion of ACS, unless absolute contraindication exists. 1

• Nitroglycerin 0.4 mg sublingual every 5 minutes for chest pain, up to 3 doses, provided systolic BP >90 mmHg and no recent phosphodiesterase inhibitor use. 1

• Morphine 2–4 mg IV for refractory chest pain unresponsive to nitroglycerin, titrated carefully to avoid hypotension and respiratory depression. 1

Hyperkalemia

Membrane Stabilization and Potassium Shift (Immediately Available)

• Calcium chloride 1000 mg (10 mL of 10% solution) IV over 2–3 minutes or calcium gluconate 3000 mg (30 mL of 10% solution) IV over 2–3 minutes for ECG changes (peaked T waves, widened QRS). 1, 2

• Regular insulin 10 units IV with dextrose 25 g (50 mL of D50W) to shift potassium intracellularly. 1

• Sodium bicarbonate 50 mEq IV for concurrent metabolic acidosis. 1, 2

• Albuterol 10–20 mg nebulized to augment intracellular potassium shift. 1

Severe Bradycardia with Hemodynamic Instability

Chronotropic Agents (Immediately Available)

• Atropine 0.5–1 mg IV every 3–5 minutes (maximum total 3 mg) for symptomatic bradycardia. 1, 2

• Epinephrine infusion 2–10 µg/min for atropine-refractory bradycardia with hypotension. 1, 2

• Transcutaneous pacing should be initiated immediately if pharmacologic measures fail or if the patient is unstable. 1

Massive Pulmonary Embolism with Hemodynamic Collapse

Thrombolytic Therapy (Available Within 1 Hour)

• Alteplase (tPA) 100 mg IV over 2 hours or 50 mg IV bolus for massive PE with shock or cardiac arrest. 1

Beta-Blocker Overdose

Antidotes and Supportive Therapy (Immediately Available)

• Glucagon 2–10 mg IV bolus, then 1–15 mg/h infusion (anticipate vomiting; have suction ready). 1, 2

• High-dose insulin euglycemia therapy: 1 U/kg IV bolus, then 1–10 U/kg/h infusion with continuous dextrose supplementation to maintain euglycemia. 1, 2

• Calcium chloride 2000 mg IV or calcium gluconate 6000 mg IV, followed by continuous infusion. 1, 2

• Atropine 0.5–1 mg IV every 3–5 minutes for symptomatic bradycardia. 1, 2

Critical pitfall: High-dose epinephrine infusion (starting at 0.1–0.5 µg/kg/min) may be required for refractory shock; standard vasopressor doses are often inadequate in severe beta-blocker toxicity. 1, 2

Calcium-Channel Blocker Overdose

Antidotes and Supportive Therapy (Immediately Available)

• High-dose insulin euglycemia therapy: 1 U/kg IV bolus, then 1–10 U/kg/h infusion with dextrose supplementation—this is more effective than calcium alone. 1, 2

• Calcium chloride 2000 mg IV or calcium gluconate 6000 mg IV, repeated every 10–20 minutes as needed, though effectiveness is variable. 1, 2

• Glucagon 2–10 mg IV bolus, then 1–15 mg/h infusion for refractory bradycardia and hypotension. 1, 2

• Norepinephrine or epinephrine infusion for persistent hypotension despite calcium and insulin. 1, 2

Cyanide Poisoning

Antidotes (Immediately Available)

• Hydroxocobalamin 5 g IV over 15 minutes is the preferred first-line antidote due to wider indications, ease of use, and superior safety profile. 1, 2

• Sodium nitrite 300 mg IV plus sodium thiosulfate 12.5 g IV is an acceptable alternative when hydroxocobalamin is unavailable. 1, 2

Critical pitfall: Hydroxocobalamin is preferred over the conventional cyanide antidote kit because it does not cause methemoglobinemia and can be used empirically in smoke inhalation victims without diagnostic confirmation. 1

Digoxin Toxicity

Antidote (Available Within 1 Hour)

• Digoxin-specific antibody fragments (Digoxin Immune Fab) 10–20 vials IV for acute, life-threatening overdose with severe bradycardia, hyperkalemia, or ventricular arrhythmias. 1, 2

Organophosphate Poisoning

Antidotes (Immediately Available)

• Atropine 1–2 mg IV, doubled every 5 minutes until bronchorrhea and bronchospasm resolve, then 10–20% of loading dose per hour as continuous infusion. 1, 2

• Pralidoxime 1–2 g IV loading dose, then 400–600 mg/h infusion to reactivate acetylcholinesterase. 1, 2

Critical pitfall: Avoid neuromuscular blockers metabolized by cholinesterase (succinylcholine, mivacurium); use rocuronium or vecuronium instead. 7

Tricyclic Antidepressant Overdose

Antidote (Immediately Available)

• Sodium bicarbonate 50–150 mEq IV bolus, then 150 mEq/L infusion at 1–3 mL/kg/h to maintain arterial pH 7.45–7.55 for QRS widening >100 ms or ventricular arrhythmias. 1, 2

Critical pitfall: Do not administer Class IA (quinidine, procainamide), Class IC (flecainide, propafenone), or Class III (amiodarone, sotalol) antiarrhythmics, which exacerbate sodium channel blockade and cardiac toxicity. 1

Local Anesthetic Systemic Toxicity

Antidote (Immediately Available)

• Intravenous lipid emulsion 20%: 1.5 mL/kg IV bolus, then 0.25 mL/kg/min infusion for up to 30 minutes for severe cardiovascular collapse or refractory seizures. 1, 2

Benzodiazepine Overdose

Antidote (Immediately Available—Use With Extreme Caution)

• Flumazenil 0.2 mg IV, titrated up to a maximum of 1 mg, only for pure benzodiazepine overdose with respiratory depression in carefully selected patients. 1, 2, 7

Critical contraindications: Chronic benzodiazepine use, seizure disorders, co-ingestion of pro-convulsant agents (tricyclic antidepressants, cocaine, bupropion), or unknown overdose circumstances—flumazenil can precipitate refractory seizures and ventricular dysrhythmias. 1, 2, 7

Critical pitfall: Flumazenil has no role in cardiac arrest caused by benzodiazepines; when in doubt, prioritize airway management and supportive care over antidote administration. 1, 2

Antidote Stocking Requirements

Immediate Availability (≤5 Minutes)

The following 23 antidotes must be immediately available in the emergency department or on crash carts 1:

• Naloxone
• Epinephrine (1:1000 for IM injection and 1:10,000 for IV)
• Atropine
• Calcium chloride or calcium gluconate
• Sodium bicarbonate
• Dextrose 50%
• Glucagon
• Activated charcoal
• Hydroxocobalamin (preferred) or sodium nitrite/sodium thiosulfate
• Flumazenil (with strict protocols)
• Lorazepam or midazolam
• Magnesium sulfate
• Albuterol
• Corticosteroids (methylprednisolone, hydrocortisone)
• Aspirin
• Nitroglycerin
• Morphine
• Amiodarone
• Lidocaine
• Insulin (regular)
• Pralidoxime
• Intravenous lipid emulsion 20%
• Phentolamine (for extravasation)

Available Within 1 Hour

An additional 14 antidotes should be available within 1 hour from pharmacy 1:

• Digoxin-specific antibody fragments
• Fomepizole (preferred over ethanol for toxic alcohol poisoning)
• N-acetylcysteine
• Alteplase (tPA)
• Phenytoin or fosphenytoin
• 4-factor prothrombin complex concentrate
• Methylene blue
• Pyridoxine
• Octreotide
• Deferoxamine
• Dimercaprol
• Succimer
• Antivenoms (region-specific)
• Botulinum antitoxin (coordinated through public health)

Critical pitfall: Fomepizole is preferred over ethanol for toxic alcohol exposure (methanol, ethylene glycol) due to simplicity of use, lack of need for pharmacy compounding, reduction in medication errors, and anticipated safety in children. 1

Monitoring and Documentation

• Continuous ECG monitoring for all critically ill patients receiving emergency medications. 1, 2

• Capnography (ETCO₂ monitoring) to confirm endotracheal tube placement and assess CPR quality (ETCO₂ ≥40 mmHg suggests return of spontaneous circulation). 1, 2

• Record exact timing of symptom onset, medication administration (drug name, dose, route), and patient response for all emergency interventions. 2

• Observe patients for at least 24 hours after severe reactions, cardiac arrest, or antidote administration, preferably in an intensive-care setting. 2