Adrenaline (Epinephrine) - The Main Squeeze
- Mechanism: Potent α (vasoconstriction) & β (↑inotropy, ↑chronotropy) adrenergic agonist.
- Indications: Cornerstone for VF/pVT, Asystole, and PEA.
- Dosage & Frequency: 1 mg IV/IO, repeated q 3-5 min.
- Routes:
- IV/IO preferred for optimal delivery.
- Endotracheal (ET) if no IV/IO access: dose 2-2.5x IV dose (e.g., 2-2.5 mg).
- Key Effects: ↑Myocardial contractility, ↑Heart Rate, ↑Systemic Vascular Resistance, ↑Coronary Perfusion Pressure (CPP), improving chances of ↑ROSC.
- 📌 Mnemonic: 'Epinephrine Elevates Everything'.

⭐ High-dose epinephrine is NOT routinely recommended in cardiac arrest due to lack of proven benefit and potential for harm.
Antiarrhythmics (Amiodarone/Lidocaine) - Rhythm Rescuers
Used for shock-refractory Ventricular Fibrillation (VF) / pulseless Ventricular Tachycardia (pVT) after adrenaline & defibrillation.
| Feature | Amiodarone | Lidocaine |
|---|---|---|
| Indications | Shock-refractory VF/pVT | Shock-refractory VF/pVT (alternative to Amiodarone) |
| MOA | Class III (K+ channel blocker) | Class IB (Na+ channel blocker) |
| Initial Dose | 300 mg IV/IO bolus | 1-1.5 mg/kg IV/IO |
| Subsequent Dose | 150 mg IV/IO (if VF/pVT persists/recurs) | 0.5-0.75 mg/kg IV/IO |
| Max Total Dose | N/A | 3 mg/kg |
| Side Effects | Hypotension, bradycardia | Neurotoxicity (SAMS: Slurred speech, Altered CNS, Muscle twitching, Seizures) |
| 📌 Mnemonic | Amiodarone for 'Arrhythmias Gone' | Lidocaine 'Lets In Na+' (blocks it) |
Other Key Drugs - Situational Saviors
- Atropine
- NOT for routine PEA/Asystole.
- Bradycardia causing arrest: 1mg IV q3-5min (max 3mg).
- Sodium Bicarbonate
- NOT routine.
- Indications: Severe metabolic acidosis, hyperkalemia, TCA overdose.
- Dose: 1 mEq/kg IV.
⭐ Routine empirical administration of sodium bicarbonate during cardiac arrest is not recommended and may be harmful.
- Magnesium Sulfate
- Indications: Torsades de Pointes, hypomagnesemia.
- Dose: 1-2 g IV diluted, over 5-20 min.
- Calcium Chloride / Gluconate
- Indications: Hyperkalemia (ECG changes), CCB/BB overdose, hypocalcemia.
- Dose: CaCl2 0.5-1g IV or CaGluconate 1.5-3g IV slowly.
ACLS Drug Pathways - The Code Blue Dance
High-quality CPR and early defibrillation are paramount for survival. Drugs via IV/IO. Adrenaline 1mg q3-5min.
- VF/pVT Pathway: CPR → Shock → CPR → Adrenaline (after 2nd shock) → CPR → Shock → Amiodarone (300mg bolus, then 150mg) or Lidocaine (1-1.5mg/kg, then 0.5-0.75mg/kg).
- Asystole/PEA Pathway: CPR → Adrenaline (ASAP).
⭐ > For Asystole/PEA, epinephrine should be administered as soon as IV/IO access is available.
High‑Yield Points - ⚡ Biggest Takeaways
- Adrenaline (1mg IV/IO): Primary drug for all cardiac arrest rhythms, given every 3-5 minutes.
- Amiodarone (300mg IV/IO bolus): First-line antiarrhythmic for VF/pVT; repeat 150mg if refractory.
- Lidocaine (1-1.5 mg/kg IV/IO): Alternative antiarrhythmic to amiodarone for VF/pVT.
- Magnesium Sulfate (1-2g IV/IO): Drug of choice for Torsades de Pointes.
- Atropine: Has NO routine role in PEA or Asystole management in current ACLS guidelines.
- Sodium Bicarbonate: Use is restricted; consider for known hyperkalemia or tricyclic antidepressant overdose.
- Calcium (Chloride/Gluconate): Indicated for hyperkalemia, hypocalcemia, or calcium channel blocker toxicity.
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