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Category: Medical

Topic: Emergency Medications

Level: EMT

Next Unit: Amiodarone

69 minute read

EMS Medications

Activated Charcoal | AlbuterolAspirin | Epinephrine | Naloxone | Nitroglycerin | Oral Glucose 

The medications that providers at the EMT level are permitted to administer can still have powerful and widespread effects on the body. They are generally used in more specific situations under more restrictive protocols than medications given at the paramedic level. This section will review the profiles of each of these drugs, with a focus on the indications, contraindications, and administration.

Drug Profile: Activated Charcoal

Trade Name(s): Aqua, Acti-dose, Liqui-dose

Classification: "Adsorbent, antidote"

Mechanism of Action

Activated Charcoal is a fine black powder that binds and absorbs ingested toxins. Once the drug or toxin binds to the charcoal then it is excreted in the feces. This prevents the toxic substance from further damaging the body or intestines. Activated charcoal is only effective in the treatment of specific poisonings and when administered close to the time of toxic ingestion.


Activated charcoal can bind to a large number of drugs and substances, far easier than describing what it binds to is what it does not bind to:

  • Iron-based medications,
  • hydrocarbons (oil, gasoline, certain cleaners), and
  • caustic substances;
  • (alcohol--see below).

The amount of time passed since ingestion is also important, with one hour after ingestion being the time when the majority of an ingested substance leaves the stomach for the intestines. Therefore giving activated charcoal before this time is ideal.


The reasons not to give activated charcoal are limited, as per above (iron, hydrocarbons, caustics). If you know a substance is not absorbed by activated charcoal, its utility is limited. Petroleum products and iron-based medications meet this contraindication.

Alcohols are not well absorbed due both the rapid absorption by the stomach and poor binding to the charcoal.

Caustics and corrosives can actually burn through the stomach lining and expose the inner tissues of the body to stomach contents. Adding activated charcoal in these situations can make patients dramatically worse.

Adverse Reactions

The adverse effects of activated charcoal are limited to the GI system in patients that do not have a perforated GI tract. It can indirectly cause nausea and vomiting due to the bland taste and volume of charcoal given. More common is constipation and diarrhea due to the irritation the charcoal can cause within the intestines. These side effects are never a reason not to give activated charcoal in patients that require it. 

Drug Interactions

If activated charcoal is taken within 2 hours of another medication it is likely to absorb that medication and render it less effective. If you administer activated charcoal ensure that it makes it into an official report at the time of patient handoff as this may affect the treatments that ALS or emergency department providers utilize.

Dosage and Administration

Activated charcoal may come in large tubes or single dose packets of varying sizes. Both premixed slurry and powdered forms are available, the powdered form can be mixed with lactated ringers, normal saline, or D5W (5% dextrose and water). D5W is by far the most humane choice due to the taste of the other two electrolyte filled solutions.

For infants under 1 year of age, provide 1g/kg of body mass.

For pediatric patients and adults provide 2g/kg of body mass.

Special Considerations

The administration of activated charcoal has not been studied in pregnant patients. However, there is no evidence to suggest it would be harmful, making it pregnancy category C. 

Never assume the administration of activated charcoal has "cured" a patient, toxic levels of a substance may be absorbed into the bloodstream even with the timely administration of activated charcoal. Always transport patients with a presentation suspicious for toxic ingestion to the nearest appropriate care center and contact medical command or poison control at the first available opportunity.

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Drug Profile: Albuterol 

Trade Name: Proventil, Ventolin

Classification: Sympathomimetic, bronchodilator

Mechanism of Action

Albuterol is a Beta agonist (primarily ß2); stimulating Beta receptors relaxes the smooth muscle in the bronchioles resulting in bronchodilation; this leads to easier airflow through the small airways if they are constricted due to chronic disease (COPD, Asthma) and/or acute irritation due to allergies or inhaled foreign substances. 

Albuterol also relaxes vascular and uterine smooth muscle and increases the heart rate. These effects are minor compared to the effect on the respiratory system.


Albuterol is used when patients have signs and symptoms of small airway flow restriction, also called "bronchospasm." Wheezing, a whistling sound in the lung fields is the classic sign that may indicate that albuterol administration is indicated. Patients with severe bronchospasm may have quiet lungs as opposed to wheezing, this is a sign that urgent intervention is needed.

A history of severe allergies, asthma, and COPD combined with the acute onset of dyspnea is the classic symptomology that should prompt you to consider administering albuterol. 

Albuterol also temporarily lowers potassium concentration in the blood by forcing it into the cells. Medical command may request you give albuterol if a patient with a history of cancer or kidney failure has changes on an electrocardiogram that suggests they may have Hyperkalemia.


Albuterol should be used with caution in patients that have conditions which may respond poorly to a sudden increase in heart rate. Coronary artery disease, stroke, past/present arrhythmias, and significant resting tachycardia are the most significantly affected and should be directly asked about. 

Hypertension, hyperthyroidism, seizure disorders, glaucoma, diabetes, and hypokalemia are also affected by albuterol, the effects of albuterol on these conditions is often dependent upon the severity of the patient's condition and are rarely significant in the EMS setting. These contraindications often appear on registry exams.

Other medications that stimulate the sympathetic nervous system can act in conjunction with albuterol to amplify the heart rate increase that it causes; use with caution in patients who have recently taken medications or drugs that activate the sympathetic nervous system. 

Adverse Reaction

The reactions to albuterol are related to its sympathetic stimulating effects. Otherwise, the drug is well tolerated and has minor side effects. Tachycardia can result with excessive use, Arrhythmia/Dysrhythmia can occur in any patient, and vasodilation of the skin, tremors, nausea, vomiting, and hyperglycemia are other rare side effects. 

Notable, bronchospasm is a severe reaction that can occur with excessive use, this is a reactive effect in the bronchioles that results from deactivation of the sympathetic receptors due to massive overstimulation. 

Drug Interactions

As mentioned in contraindications. Patients taking drugs that stimulate the sympathetic nervous system can interact significantly with albuterol. The ones you will encounter most often are cocaine, tricyclic antidepressants, and monoamine oxidase inhibitors. 

Adult Dosage

Albuterol is given via nebulizer. It is stocked in most BLS and ALS ambulances as a 2.5mg ampule of premixed solution. A single ampule of this solution should be placed in a nebulizer (also called a "small volume nebulizer - SNV")  or in line with a full facemask or a positive pressure ventilation device. The oxygen flow rate while giving albuterol should not exceed 6 L/min. 

Pediatric Dosage

For children under 40 lbs, administer one half of the standard 2.5mg ampule and add 1.5ml of normal saline and administer via SVN with a mouthpiece.



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Drug Profile: Aspirin

Trade Name: Ecotrin

Classifications: "Salicylate," antiplatelet, antipyretic, analgesic

Mechanism of Action

Aspirin inhibits the activation of platlets, which stops them from sticking to each other or the blood vessel walls, lowering the rate of clot formation. It does this by stopping the production of a chemical called cyclooxygenase (COX) which is needed to make Thromboxane A2 which is what triggers platelets to aggregate.

It lowers inflammation and lowers pain by inhibiting the production of chemicals called "prostaglandins."

Aspirin reduces fever by causing the brain to increase blood flow to the skin which increases heat loss into the air and sweating.


The EMS use of aspirin is generally limited to cases of suspected heart attack. 


Certain individuals have a hypersensitivity to aspirin, this most often takes the form of asthma attack like episodes when taking aspirin or NSAID's, ask for a history of this reaction and treat as an asthma attack if it occurs. Patients currently having an asthma attack may be worsened by aspirin, this is due to the effects of prostaglandins on the airways.

Current use of anticoagulants is a contraindication unless otherwise instructed by medical command, as significant bleeding can result. Many patients that are of advanced age will be on anticoagulants, they also have a higher baseline risk of bleeding even without medications, exercise caution in individuals over the age of 80. 

The existence of severe GERD or suspicion of a stroke is a contraindication as anticoagulation can predispose these patients to dangerous bleeding. Other diseases that predispose patients to sudden bleeding should also lead you to avoid administering aspirin. 

Pediatric patients should never be given aspirin, if given in the setting of a viral illness aspirin can cause fatal organ damage in children. 

 Side Effects

Mild overdoses of aspirin can result in significant dizziness, nausea, vomiting, abdominal pain, and the expected easy bruising and bleeding. In very large amounts, it can cause acidosis, alkalosis, and fever.

Dosage and Route

Aspirin is given by mouth in 324mg at a time. Aspirin comes in 81mg and 324mg tablets, The 81mg tablets are often called "baby aspirin" and are sometimes chosen over a standard aspirin tablet because they are chewable. If you are giving baby aspirin, 4 tablets of 81mg constitute a single dose.

Pediatric Dosage

Do not use in children. 


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Drug Profile: Epinephrine

Trade name: Adrenalin, Epi-Pen

Classification: Sympathomimetic

Mechanism of Action

A naturally-occurring hormone that acts directly on the alpha- and beta-adrenergic receptors found all over the body, but most importantly in the blood vessels. This causes positive inotropic (heart contraction strength) and chronotropic (heart rate) effects as well as increased systemic vascular resistance (constriction of the blood vessels). These effects combine to dramatically increase the blood pressure.


Epinephrine is used when dramatic and immediate activation of the sympathetic nervous system is needed. In the EMS setting, this comes into play when circulation is compromised due to loss of cardiac output or loss of systemic vascular resistance. Note that both of these things will result in low blood pressure as they are a part of the blood pressure equation. 

Blood Pressure = (Cardiac Output) x (Systemic Vascular Resistance)

The loss of cardiac output refers to cardiac arrest and symptomatic bradycardia. If a patient in cardiac arrest is exhibiting a rhythm consistent with asystole, ventricular fibrillation, pulseless ventricular tachycardia, or pulseless electrical activity, the use of epinephrine is indicated. The other common indication is in patients whose heart is still beating, but is beating slow enough that it is causing hypoxemia, this is known as symptomatic bradycardia.

The loss of systemic vascular resistance is the other indication for epinephrine usage, specifically the condition of anaphylaxis; the extreme allergic reaction that results in specific individuals whose bodies are hypersensitized to specific allergens. Epinephrine acts on the sympathetic receptors in the blood vessels, causing them to clamp down, and in the heart causing it to beat faster and harder.

Finally, epinephrine is used in severe asthma attacks that are not responding to albuterol in the field, this use is very rare and is generally reserved for emergency departments.


Epinephrine should always be used for patients in anaphylaxis and in patients with cardiac arrest. There are rare hypersensitivities to epinephrine that leads to extreme increases in blood pressure and heart rate. Do not let fear of these conditions stop you from administering epinephrine when it is indicated.

Dosage and Route during Cardiac Arrest

During a cardiac arrest, the use of epinephrine is part of the ACLS algorithm, for review the timelines and dosing are reviewed below. Keep in mind that epinephrine can be administered through an endotracheal tube (ET) or into the veins (IV) each of which demands a different concentration for dosing. These amounts and concentrations should be memorized, as their rapid and appropriate use during ACLS is essential to patient outcomes.


Adult: 1.0mg of 1:10,000 IV q 3 - 5 minutes

Pediatric: 0.01mg/kg of 1:10,000 IV/IO


Adult: 2.0 - 2.5mg of 1:1,000 ET q 3 - 5 minutes

Pediatric: 0.1mg/kg of 1:1,000 ET q 3 - 5 minutes

Dosage and Route during Severe Anaphylaxis/Asthma Attach

Anaphylaxis and severe asthma attacks utilize the same algorithm for the administration of epinephrine. The Intramuscular (IM) method of administration is clasically done via EPI-PEN, an autoinjector device that is designed to be usable by a victim themselves. In some jurisdictions, your ambulance may be equipped with these devices. If not, administration into the anterolateral thigh or deltoid can be done with any standard syringe and hypodermic needle (14 to 22 gauge 0.5 to 1.5 inch). Subcutaneous (SUBQ) administration is just as effective and only slightly slower in speed of onset, in obese patients, SUBQ administration may be required.

When assisting patients who have an Epi-Pen autoinjector, remember to instruct the patient to leave the needle in their skin for at least 10 seconds to ensure maximum uptake of the medication into the tissues.

Adult Dosing: 0.3 - 0.5mg of 1:1,000 IM q 5 - 15 minutes, if patient deteriorates 0.1 - 0.5mg of 1:10,000 IVP q 5 - 15 minutes.

Pediatric Dosing: 0.01mg/kg of 1:1,000 IM (6% to 19% require a second dose), if patient deteriorates 0.1 - 0.5mg of 1:10,000 IVP q 5 - 15 minutes.

Deterioration in the setting of anaphylaxis or severe asthma attack is defined as unconsciousness, a drop of SPO2 below 92%, or suspicion for complete airway obstruction.

Dosage and Route for Symptomatic Bradycardia


  • 0.01mg/kg of 1:10,000 IV/IO or
  • 0.1mg/kg of 1:1,000 ET q 3 - 5 minutes

Dosage and Route for Symptomatic Bradycardia (as an infusion)

Preparation: 1 mg of 1:1,000 in 250mL NS


  •  2 - 10mcg/min


  •  0.1 - 1mcg/kg/min


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Drug Profile: Naloxone

Trade Name: "Narcan"

Classification: Opioid Antagonist

Half-life:  2 hours


Narcan acts as a "competitive opioid antagonist," it attaches to the same receptors used by opioid medications but does not activate said receptors. This causes the effects of acute and chronic opioid use to be nearly instantly reversed. 


Narcan is used when a patient is exhibiting profound respiratory or CNS depression that may be a threat to life in the suspected setting of opioid use. This condition is known as an "opioid overdose" and generally occurs in the setting of heroin abuse, chronic prescription painkiller abuse, or intentional/accidental acute excess ingestion.


Known sensitivity to Narcan is its only contraindication. This is less relevant in actual practice as most patients requiring Narcan are in no shape to tell you their medical history.

Narcan near instantaneously removes the effect of opioids which causes a rush of sympathetic stimulation, for this reason, its use in patients with arrhythmias, cardiac disease, or recent head trauma should be followed with very close monitoring. Aggressive sympathetic stimulation can aggravate these conditions.

Adverse Effects

The adverse effects of Narcan can be grouped into the immediate state of withdrawal it induces and the potential consequences of that withdrawal.

Opioid withdrawal is an unpleasant and drawn out process, patients who are put into withdrawal due to Narcan administration are likely to be significantly agitated and potentially a danger to others. Some of the symptoms that are experienced in withdrawal are: Nausea, vomiting, diaphoresis, and combativeness. Be cautious when administering Narcan, doing so without backup available may be unwise.

The sympathetic stimulation resulting from withdrawal leads to: tachycardia, hypertension, and an increase in intracranial pressure (ICP). If a patient has a history of cardiac problems the tachycardia can induce arrhythmia, cardiac ischemia, or full-blown cardiac arrest. Likewise, the increase in ICP can make existing brain swelling from recent head trauma life-threatening and/or increase the risk of seizure in patients with a seizure disorder. 

Dosage and Route

Narcan for EMS use comes in a nasal, intramuscular (IM), subcutaneous (SQ), and intravenous (IV) formulation. Generally, EMT and Paramedic providers will be provided with the IV formulation, but this may vary based on your local jurisdiction and protocols. Keep in mind that the dosing of Narcan is highly variable, the goal of Narcan is never to force the patient into full withdrawal, only give the minimum required to restore the patient's ventilatory capacity.

Keep in mind that the half-life of Narcan is far shorter than most opioids, re-dosing of Narcan may be needed if transport times will exceed 45 to 60 minutes. 

Adult Dosing

An initial dose of 0.4mg to 2.0mg via IV/SQ/IM repeated q2-3m not to exceed 10mg. 

A nasal spray that comes in 2.0mg or 4.0mg doses is available, this is generally only used by bystanders before EMS arrives.

The initial dose chosen is up to the provider, keep in mind the severity of the patient's respiratory depression and the difficulty of restraining a severely withdrawing patient if too large a dose is administered. 

Pediatric dosing (UNDER 5 yo)

0.1 mg/kg, the remainder of instructions are identical to above.


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Drug Profile: Nitroglycerin

Trade Name: Nitrostat

Classification: Nitrate, Vasodilator

Mechanism of Action

Nitrates are rapid vascular smooth muscle relaxants that dilate the veins in the body and lower the preload to the heart. They also increase blood flow to the heart by dilating the coronary arteries. The combination of these effects reduces the amount of oxygen the heart requires, potentially relieving chest pain from coronary ischemia.


The primary indication for nitrates is in chest pain that is suspected to be due to low blood flow to the heart (angina pectoris and myocardial infarction). Nitrate administration improves pain and outcomes in patients with non-right-sided myocardial infarctions.

In patients with heart failure nitrates reduce the blood pressure and the preload going into the heart, improving its ability to contract and maximizing cardiac output. This makes them a primary EMS intervention in patients who have symptoms of heart failure exacerbation. 

In patients with pulmonary edema, nitrates are often used as the diversion of blood into the venous system makes the amount of fluid in the lungs decrease. Many cases of pulmonary edema are secondary to heart failure.


The top contraindication for nitrate administration is the suspected presence of a right-sided myocardial infarction, the right side of the heart is highly dependent upon preload, which nitrates lower. If the right side of the heart is not pumping well due to an infarct and preload is suddenly dropped, it is possible that forward blood flow in the heart will cease. The classic signs of a right-sided infarction are distended neck veins, clear lung fields, and hypotension.

There are patients who are hypersensitive to nitrates resulting in dramatic hypotension, avoid their use in these patients. Hypersensitivity to nitrates can be induced by erectile dysfunction medication, it is important to ask about the recent use (last 48hrs) of these medications! (Viagra, Cealis, Stendra, Levitra).

Hypotension is a contraindication to nitrate use, as they can excessively lower preload in these patients. This most often comes into play with patients in shock due to a cardiogenic or non-cardiogenic cause. 

Headtrauma and other conditions that increase intracranial pressure are contraindications to nitrate use. Lowering the blood pressure in these patients will decrease the amount of blood flow to the brain dramatically. 

Nitroglycerine via the endotracheal (tube) route is contraindicated, because its absorption is poor and its effects unpredictable.


Watch vitals closely, as nitrate medication can cause significant hypotension in some patients. Do not allow patients to ambulate on their own after giving nitrates, as they may become orthostatic and fall. 

Side effects

The most common side effects of nitrates are hypotension, palpitations, tachycardia, syncope, dizziness, and nausea/vomiting. These are all directly related to the blood pressure lowering effects of the medication.

Dry mouth, headache, and rashes can also result depending on how the individual patient's body reacts to the medication.


Alcohol, beta blockers, and erectile dysfunction medication can all increase the effects of nitrates and result in significant hypotension.

Dosage and Route

Nitroglycerin comes in the form of a tablet, a paste, and an oral spray. It is also provided as an IV formulation but this is not routinely used in the EMS setting. 

Tablets are the most commonly carried form give 0.3mg to 0.6mg every 5 minutes up to 3 doses as long as the blood pressure remains above 100mmhg, tablets should be dissolved under the tongue.

For the oral spray, administer one or two sprays under the tongue every 5 minutes up to 3 times, as long as the blood pressure remains above 100mmhg. The spray should be placed under the tongue as to minimize the amount inhaled.

Nitropaste is dosed in "inches," place the paste on the provided wax paper and cover one to two of the "inch marks" on the paper. Always use gloves as this medication is rapidly absorbed!

Nitroglycerin has a half-life of one to four minutes, the maximum of 3 doses applies to a 15 minute period, long transport times may mandate additional medication. Ensure that the patients' blood pressure is stable before administering additional doses. The oral form of the medication takes effect in 1 to 3 minutes, while nitropaste can take up to 30 minutes to achieve maximal effect. 



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Drug Profile: Oral Glucose

Trade Name: Insta-Glucose

Classification: Hyperglycemic

Mechanism of Action

Rapidly increases blood glucose levels by providing glucose directly, bypassing the normal processes of carbohydrate breakdown that are normally required to create glucose from ingested food.


Oral glucose is used in patients who are suspected of, or confirmed to have, hypoglycemia. It is often given empirically in known diabetics that are tremulous, tachycardic, diaphoretic, and exhibiting mild alterations in mental status. 


The primary contraindication of oral glucose is a significantly decreased mental status that makes oral medications unsafe to administer. The exact level of mental status change that makes glucose unsafe is up to the individual responder but the absolute contraindication is an inability to follow basic commands or complete unresponsiveness. 

Nausea and vomiting is another contraindication as the medication must pass through to the intestines to be effective, vomiting may result in the medication leaving the body and the patient becoming increasingly hypoglycemic while you wait for it to take effect. 

Drug Interactions

There are no known major drug interactions with oral glucose. Caution should be used in patients suspected of alcoholism as supplying glucose without IV hydration and IV thiamine (commonly called a banana bag) can result in central nervous system damage. 

Dosage and Administration

Oral glucose comes in several forms, all of which are packaged in single-dose containers. There are gels, fluid, and solid formulations. Each should be consumed by the patient slowly over the course of several minutes. Monitor the patient's clinical status, if no improvement is seen after 15 minutes a second dose should be provided. Minimize the amount of water and solid food eaten after the glucose is given to minimize the risk of vomiting. 

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