Epinephrine: Composition, Role in the Human Body, Medical Uses and Adverse Effects

It is also commonly known as adrenaline. It consists of a hormone secreted by the adrenal glands.

As it is also known, adrenaline was initially used as a trademark for a product manufactured by an American pharmaceutical firm called Parke, Davis & Co. The use of words today is indistinct since it is assumed that it is the same.

Structuring or composition of Epinephrine

This Epinephrine is derived from tyrosine, which is an amino acid. Epinephrine is sometimes called catecholamine because it contains catechol among its components. This is a molecular fraction contained in group C6H4 (OH) 2.

Dopamine and norepinephrine are also known as catecholamines. They are also synthesized from tyrosine and contain the catechol component.

What role does Epinephrine play at the body level?

Epinephrine is involved in the fight response in humans.

The fight response occurs at the moment when a person is subject to a threat. This causes a signaling process to happen that causes the body to react to a latent and every possible danger.

Specifically, the moment a threat is perceived, a signal is sent to the brain. This sends nerve impulses to the adrenal gland.


The moment the nerve signal reaches the adrenal gland, the chromaffin cells in the marrow of the adrenal gland release epinephrine.

The Epinephrine then enters the bloodstream. Therefore, it is transmitted throughout the body to cells in several places, where it initiates several responses.

Despite initiating several different responses, the effects of the use of Epinephrine have a collective purpose: to provide energy so that the body’s main muscles can respond to the threat detected.

Liver cells

One of the places where Epinephrine has an effect is in the liver.

In association with another hormone known as glucagon, Epinephrine is responsible for the breakdown of glycogen in liver cells. Glycogen is a form of energy reserve used by animals.

Epinephrine binds to a receptor outside the liver cell, causing a conformational change.

This modification implies that a G protein can now be integrated. Consequently, adenylate cyclase and ATP can bind to the complex.

Adenylate cyclase breaks down ATP into a second messenger molecule called cyclic AMP, commonly called cAMP.

This second messenger molecule then causes a protein called a kinase, which activates phosphorylase, to start. Phosphorylase is an enzyme that catalyzes the breakdown of glycogen in glucose.

The skin

Its binding mainly causes the effects of Epinephrine on the skin to alpha-adrenergic receptors, such as the alpha-2-adrenergic receptor in particular.

The restriction of the arteries has its origin in the union of Epinephrine with said alpha-adrenergic receptors. This cuts off the blood supply that goes to the skin.

A signaling cascade is also stimulated with this. This results in the cellular contraction of the smooth muscle in the skin, which causes the elevation of the superficial hairs of the skin.


The lungs have smooth muscles inside. Epinephrine causes the smooth muscles to relax.

Specifically, Epinephrine binds to beta-2-adrenergic receptors in bronchiole muscle cells. This facilitates the relaxation of the bronchioles, which allows intensified and deep breathing.

The heart

Epinephrine binds to the beta-adrenergic receptors contained in the heart muscle cells. This causes the rate of heart contraction to increase. This eventually leads to a more excellent blood supply to the body’s tissues.

Medical uses of Epinephrine

Epinephrine is used in a medical context. One of the best-known uses is epinephrine injections to relieve the symptoms of allergic reactions. Epinephrine is also sometimes used in cardiopulmonary resuscitation (CPR).

Epinephrine injections for allergic reactions

Perhaps one of the best-known uses of Epinephrine is in injections for life-threatening allergic reactions.

These potentially fatal allergic reactions are known as global anaphylaxis and can be caused by:

  • Insect bites and stings – bee and wasp stings in particular
  • Foods such as nuts, milk, seafood, etc.
  • Some medications, such as some forms of antibiotics
  • Latex

The common symptoms of anaphylaxis are:

  • Respiratory difficulties and wheezing, caused by narrowing of the respiratory tract
  • Low or low blood pressure is often related to feeling faint
  • An itchy rash that consists of raised red bumps called hives
  • Swelling of the eyes, lips, hands, and feet
  • Nausea and vomiting
  • A metallic and unpleasant taste in the mouth

Epinephrine injections work to decrease the symptoms of anaphylaxis by:

  • Open airways to reduce breathing difficulties
  • Narrow blood vessels to fight low blood pressure and relieve weak feelings.

However, Epinephrine has a short half-life, so the relief of symptoms is only temporary. Consequently, the individual should be taken immediately to the hospital.

Use of Epinephrine in Cardio-Pulmonary Resuscitation (CPR)

Epinephrine is sometimes used in CPR since it stimulates adrenergic receptors.

It stimulates the increase of alpha and beta-adrenergic receptors, resulting in improved cerebral and myocardial blood flow.

CPR is more effective in maintaining a central blood pool due to more excellent peripheral resistance.

However, there are potential side effects of the use of Epinephrine since it has been linked to brain and heart damage.

Extensive treatment with Epinephrine causes the cellular increase in the cardiac muscle. This is partly due to the activation of the protein kinase cascade activated by a mitogen (MAP). This can lead to cardiac hypertrophy.

Cardiac hypertrophy decreases the size of the chambers of the heart, particularly the left and right ventricles.

Sometimes, cardiac hypertrophy can cause heart disease.

An important detail to know

The epinephrine solution deteriorates rapidly when exposed to air or light, turning pink from adrenochrome oxidation and brown from melanin formation.

What are the potential adverse effects of the epinephrine injection?

Before using Epinephrine a second time, call your doctor if your first injection caused a severe side effect such as increased respiratory distress or blood pressure at dangerously high levels (severe headache, blurred vision, ringing in the ears, anxiety, confusion, chest pain, shortness of breath, irregular heartbeat, seizures).

Side effects that may be less serious may include:

  • Perspiration
  • Nausea and vomiting
  • Pale skin
  • Feeling short of breath
  • Dizziness
  • Weakness or tremors
  • Headache or
  • Feeling nervous or anxious

This is not a complete list of unwanted effects that may occur. Call your doctor to get medical information about side effects.

What is the most important information I should know in advance about epinephrine injection?

Before using this medication, notify your doctor if you have heart disease or high blood pressure, a heart rhythm disorder, coronary artery disease, Parkinson’s disease, diabetes, or a thyroid disorder.

Before using Epinephrine, tell your doctor about all other medications you use, especially digoxin (digital, Lanoxin), heart or blood pressure medications, heart rhythm medications, an antidepressant, a diuretic (water), medications for the thyroid, migraine medication, or sleeping medication containing an antihistamine or an MAO inhibitor such as Marplan, Nardil, Azilect, Eldepryl, Emsam or Parnate.

Seek emergency medical attention even after using Epinephrine to treat a severe allergic reaction. The effects of adrenaline can subside or go away after 10 or 20 minutes. You should receive more treatment and observation.

Before using Epinephrine a second time, tell your doctor if your first injection caused a severe side effect such as increased respiratory distress or higher blood pressure than expected (severe headache, blurred vision, ringing in the ears, anxiety, confusion, chest pain, shortness). Of breath, irregular heartbeat, convulsions).

What should I discuss with my health care provider before using epinephrine injection?

To make sure you can use Epinephrine safely, tell your doctor if you have any of these other conditions:

  • Heart disease or high blood pressure
  • A heart rhythm disorder
  • Coronary artery disease
  • Parkinson’s disease
  • Diabetes or
  • A thyroid disorder.

Do not use Epinephrine if you are pregnant or breastfeeding a baby without your doctor’s advice.

In an emergency, it is possible that before using adrenaline, you can not inform the people who care for you if you are pregnant or breastfeeding. Make sure any doctor caring for your pregnancy or your baby knows that you have received this medicine.

How should I use it?

Use exactly as prescribed by your doctor. Do not use it in higher or lower amounts or for longer than prescribed by your doctor. Follow the instructions printed on the medication label.

Seek emergency medical attention even after using this medication to treat a possible allergic severe reaction. The effects of Epinephrine may disappear after 10 or 20 minutes. You should receive more treatment and observation.

The autoinjector device included in this medicament is a disposable, single-use system containing a spring needle for injection.

The epinephrine injection comes with a guide for the patient for safe and effective use. Follow them carefully. Ask your doctor or pharmacist if you have any questions.

Do not remove the safety cap until you are ready to use the autoinjector. Never place your fingers on top of the tip when removing the safety cap or after removing the safety cap.

To use an epinephrine autoinjector:

Form a fist around the autoinjector with the black tip pointing down. Remove the safety cap.

Place the black tip against your outer thigh’s softest and fleshy portion. You can apply the injection directly through your clothes. Do not place your thumb on the end of the unit.

With a quick movement, push the autoinjector firmly against your thigh. This will release the spring needle that injects the dose of Epinephrine. Keep the autoinjector in place for a few moments after activation.

Remove the autoinjector from your thigh. Carefully reinsert the used device with the tip of the needle into the transport tube. Re-cover the box and take it with you to the emergency room so that anyone who treats you knows how much Epinephrine you have received.

Use each autoinjector only once. Discard it after one use, even if you still have some medication left.

Do not use the medication if it shows a different color or has visible particles or if the date of the true vine indicated on the label has passed. Call your doctor to get a new prescription.

Store at room temperature away from humid, hot, and excessively bright places. Do not refrigerate or store it in automotive vehicles.

What happens if I miss a dose?

Since epinephrine injection is used at the standard level only when necessary (i.e., in an emergency), it is not likely to have a specific dosing schedule. Do not repeat the doses of Epinephrine without the specialized advice of a doctor.

What happens if an overdose occurs?

Symptoms of overdose may include a fast or pounding heartbeat, sudden severe headache, unexpected numbness or weakness, feeling like you might pass out, wheezing, shortness of breath, chest pain, or sudden problems with a vision: speech, or the balance.

What should I avoid while using epinephrine injection?

Do not inject Epinephrine in an intravenous line or the muscle area of ​​the buttocks, or it may not work as well. Inject only in the fleshy and soft outer part of the thigh.

Accidental injection of Epinephrine into the hands or feet can cause loss of blood flow in those areas and the resulting numbness. If this occurs, seek emergency medical attention.

What other drugs affect?

Tell your doctor about any other medicine you are taking, without omitting any, especially if it is:

  • Digoxina (digital, Lanoxin, Lanoxicaps);
  • Any diuretic (water pill);
  • levothyroxine (Levothroid, Levoxyl, Synthroid, Unithroid);
  • Chlorpheniramine or Diphenhydramine (antihistamines commonly found in medicines for cold, allergy, or over-the-counter medications);
  • An antidepressant such as Amitriptyline (Elavil, Etrafon), Doxepin (Sinequan), Imipramine (Janimine, Tofranil), Nortriptyline (Pamelor) and others;
  • Un betabloqueador como Atenolol (Tenormin, Tenoretic), Carvedilol (Coreg), Labetalol (Normodyne, Trandate), Metoprolol (Lopressor, Toprol), Nadolol (Corgard), Propranolol (Inderal, InnoPran), Sotalol (Betapace) y otros;
  • Others such as Ergotamine (Ergomar), Dihydroergotamine (DHE 45, Migranal Nasal Spray), Ergonovine (Ergotrate), or Methylergonovine (Methergine);
  • Heart rhythm medications such as Quinidine (Quin-G); or an MAO inhibitor such as Furazolidone (furoxone), Isocarboxazide (Marplan), Phenelzine (Nardil), Rasagiline (Azilect), Selegiline (Eldepryl, Emsam, Zelapar) or Tranylcypromine (Parnate).

This list is incomplete, and other drugs may also interact with Epinephrine. Tell the doctor all the medicines you take. This includes prescriptions, over-the-counter vitamins, and herbs. Do not start taking a new medication without telling your doctor.

Where can I get more information?

Your doctor or pharmacist can provide more information about epinephrine injection.

Remember, keep this and all other medications out of the reach of children, never give your medicines to others, and use this medication only for the prescription prescribed to you by your doctor.