Reference — Emergency Nursing · Pharmacology

Emergency Medications Reference

Quick reference for essential emergency medications — dosing, indications, mechanism, key nursing considerations, and NCLEX pearls for epinephrine, amiodarone, adenosine, atropine, antidotes, and more.

Emergency Nursing · Pharmacology

Educational use only. Always verify doses with current clinical references and institutional protocols. Drug dosing is individualized by patient weight, condition, and clinical context. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.

Epinephrine (Adrenalin)

Catecholamine / Vasopressor / Adrenergic agonist

Indications & Dosing	•Cardiac arrest (VF, pVT, PEA, asystole): 1 mg IV/IO q3–5 min •Anaphylaxis: 0.3–0.5 mg IM (1:1000 concentration) into lateral thigh; repeat q5–15 min •Symptomatic bradycardia (last resort after atropine/pacing): 2–10 mcg/min IV infusion •Severe bronchospasm/asthma: 0.3 mg IM (1:1000) or nebulized 2.25% racemic epi
Mechanism	Alpha-1: vasoconstriction (increases perfusion pressure). Beta-1: increased HR and contractility. Beta-2: bronchodilation.
Key Notes	–Cardiac arrest: 1:10,000 concentration IV. Anaphylaxis: 1:1,000 concentration IM — concentrations are 10× different. –In anaphylaxis: IM lateral thigh (NOT deltoid) — faster absorption. IV route for cardiac arrest or refractory anaphylaxis with IV access. –Beta-blocker patients may not respond fully — add glucagon.
NCLEX Pearl	Epi q3-5min ALL cardiac arrest rhythms. Anaphylaxis = IM 1:1000 first-line. Concentration difference is a key safety question.

Atropine (generic)

Anticholinergic / Vagolytic

Indications & Dosing	•Symptomatic bradycardia (hemodynamically unstable): 0.5–1 mg IV; repeat q3–5 min; max 3 mg total •Organophosphate / cholinergic toxicity: 2–4 mg IV; repeat until secretions dry (titrate to secretions, NOT heart rate) •NOT used in cardiac arrest (removed from 2020 AHA arrest algorithms)
Mechanism	Blocks muscarinic acetylcholine receptors → decreases vagal tone → increases SA node automaticity and AV conduction.
Key Notes	–Minimum dose: 0.5 mg IV — doses < 0.5 mg may paradoxically worsen bradycardia (central vagal stimulation). –Atropine does NOT work in denervated hearts (heart transplant patients) — use pacing. –Organophosphate dosing can be massive — titrate to dry secretions, not HR.
NCLEX Pearl	Atropine NOT in cardiac arrest. Minimum 0.5 mg dose. Cholinergic toxicity: titrate to dry secretions.

Adenosine (Adenocard)

Antiarrhythmic (Class V) / AV nodal blocker

Indications & Dosing	•SVT (supraventricular tachycardia with narrow complex): converts to sinus rhythm •Diagnostic: slows ventricular rate to reveal underlying atrial rhythm in WPW/flutter
Mechanism	Inhibits AV node conduction transiently — interrupts re-entry circuits through AV node.
Key Notes	–Dose: 6 mg IV RAPID PUSH; if no effect in 1–2 min, 12 mg rapid push; may repeat 12 mg once more. Push as fast as possible (half-life < 10 sec). –MUST flush immediately with 20 mL NS rapid bolus using stopcock technique — drug is inactivated in blood within seconds. –Use most proximal IV or antecubital site. Central line preferred if available. –Transient side effects: flushing, chest tightness, sense of doom — warn patient. Brief asystole/pause is expected and transient. –Contraindicated: 2nd/3rd degree heart block, sick sinus syndrome (without pacemaker), WPW with pre-excitation (can accelerate accessory pathway). –Higher doses needed if patient on dipyridamole/theophylline. Lower doses in heart transplant patients (denervated — exquisitely sensitive).
NCLEX Pearl	6 mg rapid push → 12 mg → 12 mg. Fast push mandatory. Flush immediately. Brief asystole is expected.

Amiodarone (Cordarone, Nexterone)

Antiarrhythmic (Class III)

Indications & Dosing	•Cardiac arrest — refractory VF or pVT (shockable rhythms after ≥ 3 defibrillations): 300 mg IV/IO bolus; 150 mg for second dose •Hemodynamically STABLE wide-complex/VT: 150 mg IV over 10 min, then 1 mg/min infusion (unstable VT with a pulse → synchronized cardioversion, not a slow infusion) •Rate control in rapid AFib/flutter (IV)
Mechanism	Blocks K⁺ channels (primary), Na⁺ channels, Ca²⁺ channels, and has non-competitive beta-blocking effect. Prolongs action potential and refractory period.
Key Notes	–Cardiac arrest dosing: IV bolus (undiluted or diluted). Post-arrest: maintenance infusion 0.5–1 mg/min × 18h. –IV amiodarone causes hypotension — monitor BP during infusion. –NOT for asystole or PEA. –Oral amiodarone: extensive side effects with long-term use (pulmonary toxicity, thyroid dysfunction, liver toxicity, corneal deposits, photosensitivity, peripheral neuropathy) — check LFTs, TFTs, PFTs regularly.
NCLEX Pearl	Amiodarone for refractory VF/pVT after ≥ 3 shocks. NOT for asystole/PEA. Know long-term side effects for chronic use questions.

Lidocaine (Xylocaine)

Antiarrhythmic (Class Ib) / Local anesthetic

Indications & Dosing	•Alternative to amiodarone for refractory VF/pVT: 1–1.5 mg/kg IV/IO; may repeat 0.5–0.75 mg/kg (max 3 mg/kg) •Post-ROSC VT suppression/maintenance: 1–4 mg/min infusion •Local/regional anesthesia
Mechanism	Blocks Na⁺ channels — stabilizes ventricular myocardium; suppresses ventricular ectopy.
Key Notes	–Preferred alternative when amiodarone unavailable. –CNS toxicity at high levels: tinnitus, numbness, confusion → seizures → cardiovascular collapse. –Reduce dose in hepatic failure and heart failure (decreased hepatic metabolism).
NCLEX Pearl	Second-line to amiodarone for VF/pVT. Signs of toxicity: tinnitus, confusion, seizures.

Magnesium Sulfate (MgSO₄)

Electrolyte / Antiarrhythmic

Indications & Dosing	•Torsades de Pointes (polymorphic VT with long QTc): 1–2 g IV over 15 min (slower if not pulseless) •Pre-eclampsia/eclampsia seizure prevention and treatment: 4–6 g IV loading dose, then 1–2 g/hr maintenance •Severe asthma exacerbation (adjunct): 2 g IV over 20 min •Magnesium deficiency
Mechanism	Stabilizes cell membranes; shortens action potential duration; inhibits calcium entry; bronchial smooth muscle relaxation.
Key Notes	–ANTIDOTE for magnesium toxicity: calcium gluconate 1 g IV. –Signs of magnesium toxicity (in order): loss of deep tendon reflexes (first sign) → respiratory depression → cardiac arrest. –Monitor: DTRs (should be present before giving next dose), urine output, RR. Hold if RR < 12 or DTRs absent. –Pre-eclampsia: do not use with calcium channel blockers simultaneously (extreme hypotension).
NCLEX Pearl	Torsades de Pointes = magnesium first-line. Pre-eclampsia: monitor DTRs, RR, UO. Antidote = calcium gluconate.

Sodium Bicarbonate (NaHCO₃)

Alkalinizing agent / Electrolyte

Indications & Dosing	•TCA antidepressant overdose (wide QRS/dysrhythmias): 1–2 mEq/kg IV bolus; target pH 7.45–7.55 •Hyperkalemic cardiac arrest: 1 mEq/kg IV (drives K⁺ intracellularly) •Documented severe metabolic acidosis (pH < 7.1) during prolonged cardiac arrest •Rhabdomyolysis: alkalinizes urine to prevent myoglobin precipitation in tubules
Mechanism	Provides bicarbonate to buffer excess H⁺; alkalinizes plasma; drives K⁺ into cells (hyper-K treatment); reverses Na channel blockade in TCA toxicity.
Key Notes	–NOT routine in cardiac arrest — may worsen intracellular acidosis and hyperosmolality. –Give for SPECIFIC indications: TCA OD, hyperkalemia, documented severe acidosis. –Separate IV line from calcium (precipitation). Do not mix with epinephrine (inactivates).
NCLEX Pearl	Bicarb = TCA OD (wide QRS + hypotension) and hyperkalemic arrest. NOT routine in cardiac arrest.

Naloxone (Narcan)

Opioid antagonist

Indications & Dosing	•Opioid overdose / toxidrome (respiratory depression, miosis, coma): 0.4–2 mg IV/IM/IN; repeat q2–3 min •Postoperative opioid reversal: smaller titrated doses (0.04–0.2 mg IV) to avoid acute pain and withdrawal
Mechanism	Competitive antagonist at opioid mu, kappa, and delta receptors — displaces opioids; reverses CNS and respiratory depression.
Key Notes	–Short duration of action (30–90 min) — many opioids outlast naloxone. Monitor for re-sedation; may need infusion for long-acting opioids (fentanyl, methadone). –Titrate to respiratory rate and SpO₂, not to consciousness — avoid precipitating acute opioid withdrawal (severe withdrawal, combativeness, cardiovascular stress). –Routes: IV, IM, intranasal (IN), subcutaneous. IN is useful in field setting (no IV required). –Intranasal dosing: 2–4 mg IN. Not absorbed as quickly as IV but effective for opioid reversal.
NCLEX Pearl	Titrate naloxone to respirations, not full reversal (to avoid withdrawal). Short duration — observe for re-sedation.

Flumazenil (Romazicon)

Benzodiazepine antagonist

Indications & Dosing	•Benzodiazepine overdose reversal: 0.2 mg IV over 30 sec; repeat q1 min; max 1 mg •Reversal of procedural sedation (benzo component)
Mechanism	Competitive antagonist at GABA-A benzodiazepine receptor — reverses sedation, anxiolysis, and respiratory depression caused by benzodiazepines only.
Key Notes	–Reverses benzodiazepines ONLY — does NOT reverse alcohol, barbiturates, opioids, or other CNS depressants. –CONTRAINDICATION: chronic benzo use (physical dependence) — precipitates acute withdrawal seizures. Also avoid in TCA co-ingestion (seizure risk) and cocaine ingestion. –Short duration (30–60 min) — patient can re-sedate after flumazenil wears off. Monitor closely.
NCLEX Pearl	Flumazenil reverses benzodiazepines ONLY. Contraindicated in benzo-dependent patients (seizure risk). Re-sedation can occur.

Dextrose (D50W) (D50W (50% dextrose in water))

Carbohydrate / Glucose

Indications & Dosing	•Severe hypoglycemia in unconscious or unable-to-swallow patient: 25 g (50 mL of D50W) IV push •Hyperkalemia (along with insulin): shifts K⁺ intracellularly — administer BEFORE or AFTER insulin to prevent hypoglycemia
Mechanism	Provides glucose directly into bloodstream for immediate metabolic use.
Key Notes	–Check blood glucose before and 15 min after administration. –D50W is highly concentrated — vesicant (causes tissue necrosis if extravasates). Confirm IV patency. –Pediatric dose: D10W or D25W (lower concentrations — avoid neuronal injury from hyperosmolality). –If no IV access: glucagon 1 mg IM/SC (works via glycogenolysis — needs glycogen stores — less effective in liver disease or malnourishment).
NCLEX Pearl	D50W for severe hypoglycemia when unable to take oral glucose. Vesicant — check IV site. Glucagon if no IV access.

Calcium Gluconate / Calcium Chloride (Various)

Electrolyte / Membrane stabilizer

Indications & Dosing	•Hyperkalemia (membrane stabilization): calcium gluconate 1–3 g IV over 10 min; repeat if ECG abnormalities persist •Hypocalcemia: calcium gluconate 1–3 g IV slowly •Calcium channel blocker or beta-blocker toxicity (high dose): calcium gluconate 3g IV bolus •Magnesium toxicity antidote: calcium gluconate 1 g IV
Mechanism	Increases threshold potential — stabilizes cardiac membranes against effects of hyperkalemia; antagonizes effects of calcium channel blockers; antagonizes magnesium.
Key Notes	–Calcium gluconate vs calcium chloride: CaCl provides 3× more elemental calcium per gram — CaCl preferred in emergency (cardiac arrest) but causes more tissue necrosis if extravasation (central line preferred for CaCl). –Calcium gluconate: safer for peripheral IV; standard choice for most indications. –Calcium DOES NOT lower K⁺ — it stabilizes the heart. Still need insulin + glucose, bicarb, kayexalate, or dialysis to lower K⁺.
NCLEX Pearl	Calcium is FIRST step in hyperkalemic emergency (membrane stabilization before K-lowering). Does not lower K⁺. Antidote to magnesium toxicity.

Related Resources

Cardiac Arrest & Resuscitation GuideEpinephrine, amiodarone, ACLS protocol, and Hs and Ts

Open →

Anaphylaxis Management GuideEpinephrine protocol — IM vs IV route, dosing, and biphasic reaction

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Toxicology for Nurses GuideAntidotes — naloxone, flumazenil, NAC, atropine in clinical context

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Standards & sources

Fact-checked Jun 20, 2026

This page is written to align with Emergency Nurses Association (ENA) · AHA ACLS / PALS Guidelines · Advanced Trauma Life Support (ATLS). It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →