ALS Medications

Cardiac arrest drugs, doses and purpose, then the vasopressors and the receptors that explain what each one does.

Advanced Life Support Concepts

ALS Medications

Cardiac Arrest Medications

Epinephrine

Indication: Used during cardiac arrest for rhythms such as: • Asystole • Pulseless Electrical Activity (PEA) • Ventricular Fibrillation (V-Fib) • Pulseless Ventricular Tachycardia (V-Tach) Purpose: Epinephrine is a vasoconstrictor and inotropic agent. It improves coronary and cerebral perfusion during cardiac arrest, increasing the likelihood of achieving ROSC (Return of Spontaneous Circulation). Dose: • 1 mg IV/IO every 3–5 minutes during cardiac arrest

Calcium Chloride

Purpose: Calcium plays a vital role in myocardial cell membrane stability and cardiac contractility. It is administered during cardiac arrest when specific underlying conditions are suspected. Indications: • Hyperkalemia: High potassium levels can lead to life-threatening arrhythmias. Calcium chloride helps stabilize cardiac cell membranes, reducing the risk of arrhythmias. • Hypocalcemia: Replaces low calcium levels that can impair cardiac function. • Calcium Channel Blocker Overdose: Helps reverse the effects on cardiac and smooth muscle by improving conduction, contractility, and counteracting vasodilation. Adult Dose: • 1 gram IV/IO (10 mL of a 10% calcium chloride solution)

Sodium Bicarbonate

Purpose: Used during cardiac arrest to treat severe metabolic acidosis, which can impair both cardiac function and cellular metabolism. By correcting acidosis, sodium bicarbonate may help improve the likelihood of achieving ROSC (Return of Spontaneous Circulation). Adult Dose: • 50 mEq IV/IO (50 mL of an 8.4% sodium bicarbonate solution)

Amiodarone

Purpose: An antiarrhythmic used during cardiac arrest for: • Ventricular Fibrillation (V-Fib) • Pulseless Ventricular Tachycardia (V-Tach) Amiodarone works by prolonging the action potential and refractory period of cardiac cells. In V-Fib and pulseless V-Tach, the ventricles are irritable and firing chaotically. By extending the refractory period, amiodarone helps stabilize the myocardium and reduce excitability. Adult Dose: • First dose: 300 mg IV/IO • Second dose (if needed): 150 mg IV/IO Post-ROSC: • If ROSC is achieved, initiate a continuous infusion of amiodarone to help maintain rhythm stability.

Lidocaine

Purpose: An antiarrhythmic used during cardiac arrest for: • Ventricular Fibrillation (V-Fib) • Pulseless Ventricular Tachycardia (V-Tach) Lidocaine works by blocking sodium channels in cardiac cells, which slows conduction and helps stabilize the cardiac cell membrane. How it works: During an action potential, depolarization begins with sodium influx. The faster this occurs, the more excitable or irritable the cell becomes. By slowing the influx of sodium, lidocaine helps calm the myocardium and reduce excitability. Adult Dose: • Initial dose: 1 to 1.5 mg/kg IV/IO • Repeat dose (if needed): 0.5 to 0.75 mg/kg IV/IO

Magnesium Sulfate

Purpose: Used during cardiac arrest to treat Torsades de Pointes (polymorphic ventricular tachycardia). Magnesium supports proper function of ion channels in cardiac cell membranes. When magnesium is low or imbalanced, it can lead to Torsades, a specific form of ventricular tachycardia. Adult Dose: • 2 grams IV/IO Post-conversion: • If effective, a magnesium infusion should be initiated to maintain rhythm stability.

Narcan (Naloxone)

Purpose: Used for the reversal of suspected opioid overdose. Opioid overdose can lead to respiratory depression, which, if untreated, may progress to respiratory arrest and cardiac arrest. Adult Dose: • 0.4 to 2 mg IV/IO/IN/IM • If the patient is without a pulse, give 2 mg IV push • If reversal is successful, a continuous infusion should be considered. Note: High doses can sometimes lead to flash pulmonary edema, which is associated with poor outcomes.

Dextrose

Purpose: Used for the treatment of hypoglycemia. Adult Dose: • 25 g IV (50 mL of a 50% dextrose solution) • If the patient responds, continue to monitor glucose levels closely. • If needed, start a D5 or D10 infusion to maintain blood glucose levels.

IV Fluids

Types: • Normal Saline (NS) • Lactated Ringer's (LR) Purpose: May be used during cardiac arrest to help replenish intravascular volume, support perfusion, and improve the chances of achieving ROSC (Return of Spontaneous Circulation).

Other ALS Medications

Atropine

Purpose: Used to treat symptomatic bradycardia by blocking parasympathetic (vagal) stimulation of the heart. This enhances conduction through the AV node, increasing heart rate. Adult Dose: • 1 mg IV every 3–5 minutes • Maximum total dose: 3 mg Important Note: Atropine may be ineffective in patients with 3rd-degree AV block. While a provider may still order it, you should be preparing for more definitive interventions, such as transcutaneous pacing.

Adenosine

Purpose: Used for the treatment of Supraventricular Tachycardia (SVT). Adenosine has a very short half-life (~10 seconds) and works by blocking conduction through the AV node. This brief interruption allows the SA node to regain control and restore normal rhythm. Administration: • Must be given as a rapid IV push, immediately followed by a 20 mL normal saline flush, to ensure the medication reaches the heart quickly before it is metabolized. Adult Dose: • First dose: 6 mg IV push • Second dose (if needed): 12 mg IV push

Vasopressors

Vasopressors Overview

Vasopressors—commonly referred to as pressors—are potent medications used to constrict blood vessels and increase blood pressure, with the primary goal of restoring tissue perfusion in patients who are severely hypotensive. In addition to vasoconstriction, some vasopressors also affect heart contractility and heart rate, while others may have pulmonary effects (e.g., bronchodilation with epinephrine).

Receptor Overview

Understanding which receptors a vasopressor stimulates helps you anticipate its effects: 1. Alpha (α) Receptors • Location: Vascular smooth muscle (blood vessels) • Effect when stimulated: Vasoconstriction, which increases systemic vascular resistance and blood pressure 2. Beta-1 (β1) Receptors • Location: Heart • Effect when stimulated: o Increases contractility (positive inotropy) o Increases heart rate (positive chronotropy) 3. Beta-2 (β2) Receptors • Location: Bronchial smooth muscle and some blood vessels • Effect when stimulated: o Bronchodilation o Vasodilation (in specific vascular beds) 4. V1 Receptors • Location: Vascular smooth muscle • Effect when stimulated: Vasoconstriction

Caution with Vasopressors

Although vasopressors can save a patient's life, they come with many possible and deadly complications. 1. Never Bolus vasopressors Complications • Increase Risk for Arrhythmias • Cardiac, Organ and Peripheral Ischemia • Tissue Necrosis from Extravasation • Rapid Increase in BP Now let's talk about specific vasopressors and why they are used in shock (to help increase the bp and ultimately help increase the perfusion to organs).

Norepinephrine (Levophed)

• Potent Alpha Agonist with Slight Beta 1 o Increases blood pressure through vasoconstriction o Helps the heart squeeze/contract a little better and faster • Can be started peripherally in emergencies (Peripheral infusion should be no more than 1-2 hours. Advocate for a central line). • Known as the "workhorse" vasopressor because it is often the first line vasopressor used for many issues. o Pressor of choice for septic shock. It can also be used as the first-line agent for neurogenic, cardiogenic and obstructive shock when needed. ▪ Also used in hypovolemic shock, however, only when the patient has been appropriately volume resuscitated (fluids, blood products). • Onset: within 1-2 minutes • Concentration: 4mg in 250mL of NS (it can also be 8mg in 250, or up to 16mg in 250) • Range and Titration Range from facility to facility (Fill out with your own facilities protocol) o Start Dose: o Titrate By: o Range/Max:

Vasopressin

• Potent V1 Agonist o Increases BP • Second-Line Agent in Septic Shock, added on after Norepinephrine(Levophed) o After constantly titrating Levophed up and nearing the max dose, notify the provider and suggest vasopressin be added. You'll notice a big difference in the bp and in perfusion. • Onset: Up to 15 minutes • Do not Titrate o Start it and leave it alone o Rate: 0.04U/min or 0.03U/min • Concentration o 20 Units in 100mL of NS (or 50 Units in 250Ml of NS)

Epinephrine

• Alpha, Beta-1, Beta-2 • Vasoconstriction, increases HR and contraction, Bronchodilation • Vasopressor of choice with anaphylactic shock and in shock states where the heart rate is low (bradycardia patients) as it will help bring the heart rate and bp up together ▪ Added on after Levophed and vasopressin in septic patients • Onset: within 1 minute • Concentration: 1mg in 250 ml or 4mg in 250 ml • Range and Titration Range vary facility to facility (Fill out with your own facilities protocol) ▪ Start Dose: ▪ Titrate By: ▪ Range/Max: • Dirty Epinephrine Drip ▪ In Emergencies when the patient is about to code, I've had providers order a "Dirty Epi Drip." Essentially you get 1mg of epi(an amp from the crash cart), and you inject it into a 1L NS bag(label it, of course). This 1L of NS with 1mg of Epi is then administered "wide open" to the patient. • The point of this is to give you enough time to stabilize the patient and then place them on an actual drip. • You should not be doing this unless your provider explicitly states they want this and your preceptor is with you. • Push Dose Epi ▪ You should also be aware that your provider may administer a push dose of Epinephrine to your patient in an emergency to bring their BP up so they don't code. It will be approximately 10 mcg. It is not in our scope to administer this, but it is good to know about it. • Epinephrine is used in a variety of ways including during Cardiopulmonary Arrest, as a Push-Dose Pressor, as a Vasopressor, and even in laceration repairs.

Phenylephrine (Neosynephrine)

• Pure Alpha o Only vasoconstriction o Be mindful that if you only increase the BP, and if too high, the body may try to bring the BP down by decreasing the heart rate. (Can cause bradycardia so be careful with bradycardic patients) • Typically an add-on vasopressor when the others have not worked. It is also used with anaphylaxis to help vasoconstrict and bring the BP back up (but remember that in anaphylaxis epinephrine is used first). • Onset: within 1 minute • Concentration: 20mg in 250ml or 50mg in 250 ml of NS • Can also be used as a push-dose vasopressor just like Epinephrine o Its typical dose for adults will be 100-200 mcg. Just like with Epi, it is not in our scope to push this, it must be the provider. • Range and Titration Range vary facility to facility (Fill out with your own facilities protocol) o Start Dose: o Titrate By: o Range/Max:

Dopamine

• Alpha, B1, and Effects on the Kidneys o Dose dependent. It can be difficult to know what effects it will have ▪ For this reason, at least in the ER, it's not really used, since we can use levophed and epinephrine, and we know what we are getting with those two. o Typically on lower doses it increases blood flow to the kidneys, and on higher doses it causes vasoconstriction, and an increase in heart contraction • Onset: within 5 minutes • Concentration: 400mg in 250ml of NS • Range and Titration Range from facility to facility (Fill out with your own facilities protocol) o Start Dose: o Titrate By: o Range/Max:

Dobutamine

• Beta-1, Beta-2 and Alpha Agonist o Primary effect is on Beta 1, especially on helping the heart contract better o Since beta 2 can also cause vasodilation, it often counteracts the effects of Alpha. It can, at times, cause more vasodilation and lead to hypotension after starting the infusion. • Its main use will be in Cardiogenic Shock from heart failure • Onset: Up to 10 minutes • Concentration: 500mg in 250ml of NS • Range and Titration Range vary from facility to facility (Fill out with your own facilities protocol) o Start Dose: o Titrate By: o Range/Max:

General Vasopressor Tips

• Start norepinephrine peripherally in emergency situations! • Pressors are typically compatible with each other. • Always have your next bag ready to go! Never let the bag run dry. • You must learn how to make a Levophed, Epi and a vasopressin drip for emergency situations or when pharmacy is not available. • You do not titrate vasopressin. • They all perform poorly in severe acidosis, except vasopressin. As my preceptor once said, "They all suck in acidosis except vasopressin." • Tidy Up! Label all your lines at the patient and by the pump! • Do not bolus! Ever. (After titrating, give them time to work) • Set your BPs to take Q5 Minutes, or quicker! So, you can keep an eye on how the patient is responding. • If you are starting a second pressor, you better be asking for an Arterial Line to closely monitor the BP. • Ask for a central line. • Keep an eye on mcg/min vs mcg/kg/min.

Updated 30 Aug 2026