5.4 Core ACLS Drugs and Doses
Key Takeaways
- Know what each medication is for before memorizing dose numbers.
- Epinephrine is central in cardiac arrest algorithms, but it does not replace CPR or shock.
- Amiodarone or lidocaine may be used for refractory VF/pVT.
- Atropine and adenosine belong to different peri-arrest rhythm pathways and should not be mixed up.
5.4 Core ACLS Drugs and Doses
ACLS pharmacology is high-yield because drug errors are easy distractors. Candidates should connect each drug to the correct rhythm, patient condition, route, and timing.
Current official baseline
The adult advanced life support guidance covers cardiac arrest rhythms, defibrillation, airway decisions, drugs, peri-arrest tachycardia and bradycardia, and termination decisions. Use the official AHA 2025 Adult Advanced Life Support Guidelines page when your course materials or training-center instructions differ from third-party summaries: AHA 2025 Adult Advanced Life Support Guidelines.
What you need to know
| Decision point | What to do |
|---|---|
| Epinephrine | Used in cardiac arrest and selected bradycardia infusion contexts. In arrest, it supports vasoconstriction during CPR cycles. |
| Amiodarone/lidocaine | Used for refractory shockable arrest rhythms and selected ventricular arrhythmia contexts according to ACLS guidance. |
| Atropine | Used for symptomatic bradycardia, with escalation to pacing or infusions if ineffective. |
| Adenosine | Used for selected stable, regular tachycardias and sometimes diagnostic help in regular monomorphic wide-complex tachycardia when appropriate. |
How this shows up on BLS/ACLS questions
BLS and ACLS items usually test priority. Read the patient state first: age, pulse status, breathing status, rhythm, stability, and number of rescuers. Then choose the action that protects perfusion, oxygenation, defibrillation timing, or the correct algorithm branch. If an answer sounds advanced but delays CPR, shock delivery, ventilation, or an urgent stability intervention, it is usually a distractor.
Scenario anchor
A stable patient has regular narrow-complex tachycardia after vagal maneuvers fail. Adenosine is a reasonable next medication. That is different from VF/pVT arrest, where shock, CPR, epinephrine, and antiarrhythmics drive the loop.
Common traps
- Using adenosine in irregular wide-complex tachycardia.
- Giving atropine for PEA because the monitor looks slow.
- Letting drug preparation interrupt CPR or defibrillation.
Study action
Write this section as a one-line rule in your own words, then test it with mixed questions from the BLS/ACLS practice bank. Do not review only the matching topic. Mix it with nearby branches so you can tell when the rule applies and when it does not. For example, compare respiratory arrest with a pulse against pulseless arrest, or compare unstable tachycardia against VF/pVT arrest. The exam rewards that discrimination more than memorizing isolated facts.
What is the initial recommended dose of amiodarone for VF/pulseless VT that persists after 2 or more defibrillation attempts?
What is the primary purpose of delivering vasopressors (epinephrine) during cardiac arrest?