Epinephrine (Injection)

Overview

Epinephrine is marketed under several names including Twinject, Auvi-Q, and Adrenaclick but is most commonly known as Epipen. Its mass market purpose is to counteract severe and potentially life-threatening allergic reactions by injecting it when these reactions begin. Used properly, it can prevent anaphylaxis and other reactions such as hives and swelling of the throat. Epinephrine auto-injectors are commonly kept on hand by people with a known history of these severe allergies for self-injection in the event of exposure to specific substances such as foods, chemicals, and insect bites/stings.

The injection of this medication has several fast-acting effects on the body including a narrowing of the blood vessels and the opening of the airway allowing oxygen to freely travel through the lungs and into the bloodstream. In emergency rooms, it is sometimes injected into patients who have suffered bleeding, shock, low blood pressure, or are in cardiac arrest as a way to stimulate breathing and restore circulation. When used properly this is a life-saving drug that remarkably increases the chance of surviving a severe allergy attack, but it also must be handled with caution as it is just as life-threatening if injected when there is no condition to counteract.

Conditions Treated

  • Allergic Reaction
  • Cardiac Arrest
  • Bleeding
  • Shock

Type Of Medicine

  • Hormone

Side Effects

Epinephrine has the potential for unwanted side effects in certain patients and some of them will be serious enough that someone afflicted with them will need to be hospitalized. While immediate medical attention will be a normal part of an incident where Epinephrine will be used, first responders or the attending physician should be immediately informed if any of these serious side effects occur.

Some serious side effects have resulted in a significant change in sensation including numbness and/or pain in areas such as the arms, back, or jaw. Another common serious side effect sees patients notice a number of complications at the injection site including numbness, cold or warm sensation, excessive bleeding, infection, inflammation, swelling, skin discoloration, uncontrollable itching, blistering, rashes, slow healing, and scarring. After taking the injection patients may feel excessively fatigued and suffer a number of debilitating conditions including blurred vision, headaches, nausea or vomiting, trembling, dizziness, or a loss of consciousness. Known serious side effects also include those associated with the circulatory system and its effect on the body including chest pain, racing heartbeat, and a pounding felt in the ears. The drug has been reported to make the patient excessively nervous or even fearful, with this terror causing restlessness, paleness of the skin, difficulty breathing, and excessive sweating. In some cases, Epinephrine has been associated with instances of patients having a stroke.

In addition to the potential danger of serious side effects when a patient takes an Epinephrine injection, there is a risk of overdose from taking too large a volume of the injection. Patients who are suffering from an overdose will display a number of symptoms including some that may be associated with allergic reactions. These include swelling of the face, ankles, or hands as well as rapid breathing. The overdose can have a significant effect on the mental state of the patient, making them agitated, confused, irritable, uncooperative, or even hostile. Patients in an overdose state may feel their muscles twitching or experience severe cramps. The skin may feel cold and clammy to the touch and the patient may experience difficulty urinating or very little urine output. Patients in a severe overdose state may become increasingly drowsy or lethargic and gradually less responsive before falling into a stupor and an eventual coma. Some patients who overdose on the drug may experience severe seizures. Other patients who demonstrate none of these effects experience depression or rapid weight gain for some time after taking Epinephrine.

Dosage

Epinephrine should be used only in an emergency situation and any family members who may need to administer the injection to a helpless or unresponsive patient should be taught how to inject it properly. The medicine is to be injected into the muscle of the outer thigh, not into veins or other parts of the body such as the buttocks. Serious side effects can result from the improper injection of this medication. The dose of this medication will come complete with an autoinjector syringe and written instructions for its use.It is advisable for any patient or caregiver that will be expected to use the autoinjector practice its use to be prepared for emergency use during an allergy emergency. To prevent accidental or unwanted use, the autoinjector will be capped with a blue or gray safety cap or release to be removed before use. Care should be taken not to put the thumb or fingers over the colored tip of the autoinjector as this may result in an accidental injection.

In some cases, one injection will not be enough to counteract a severe allergic reaction. However, a maximum of two injections should be administered. If more injections are necessary they should be administered only under direct medical supervision. Used autoinjectors should be placed on the patient so that medical responders can know how many injections have been given in order to prevent overdose. In injecting a child, it is very important to hold the thigh in place and restrict movement before injecting Epinephrine. Allergy sufferers should carry this medicine at all times for emergency use.

When Epinephrine is injected as an emergency countermeasure for an allergic reaction the following dosages will generally be followed. Adults and children who weigh more than 30kg will receive one or two 0.15 mg SC/IM autoinjectors based on the severity of the reaction, with the second dose being administered 5-15 minutes after the first. Children weighing between 15kg to 30kg should receive one 0.3 mg SC/IM with a second dose coming between 5-15 minutes after the first. For children under 15kg use of this medication should be determined by a pediatrician.

Interactions

Certain medications will have an adverse reaction when used with Epinephrine and in some cases, they should not be used together at all. In an emergency situation, however, this may be unavoidable. It is very important that your doctor know all medications you are taking so that precautions can be taken to minimize the chance of a severe drug interaction when Epinephrine is used in an emergency. Such precautions may include substituting medications or changing dosages to mitigate this risk. The following medications are not a complete list of medications which may have an interaction with Epinephrine, but they have been listed because they are potentially serious. While use of these medications together is not recommended they may continue to be prescribed if there are no suitable alternatives for the condition they are treating.

  • Dihydroergotamine
  • Isocarboxazid
  • Linezolid
  • Phenelzine
  • Tranylcypromine

While the following drugs may come with an interaction warning with Epinephrine that may affect the effectiveness of one or both drugs. However, they may be deemed medically necessary and there may be some steps that can be taken to mitigate potential risks such as changing dosage levels.

  • Amitriptyline
  • Amoxapine
  • Bucindolol
  • Carteolol
  • Carvedilol
  • Clomipramine
  • Desipramine
  • Digoxin
  • Dilevalol
  • Dothiepin
  • Doxepin
  • Entacapone
  • Halothane
  • Imipramine
  • Iobenguane I 123
  • Levalbuterol
  • Levobunolol
  • Lofepramine
  • Metipranolol
  • Nadolol
  • Nortriptyline
  • Opipramol
  • Oxprenolol
  • Penbutolol
  • Pindolol
  • Propranolol
  • Protriptyline
  • Rasagiline
  • Sotalol
  • Tertatolol
  • Timolol
  • Trimipramine
  • Use of Labetalol with Epinephrine together may dramatically increase the chance of side-effects associated with one or both of these drugs. Ask your physician for additional guidance regarding these risks.

Medical problems that the patient suffers from may affect the use of Epinephrine and a doctor should be fully appraised of any of these in a patient's medical history prior to prescribing this medication for emergency use. Use of Epinephrine may make these conditions worse or they could reduce the effectiveness of the medication in treating anaphylaxis.

  • Angina
  • Asthma
  • Blood vessel problems
  • Depression
  • Diabetes
  • Heart attack
  • Heart disease
  • Heart rhythm problems
  • Hypertension
  • Hyperthyroidism
  • Parkinson's disease

If you have any additional questions about a medical condition and its effect on the use of Epinephrine consult with your physician.

Warnings

In the event of a severe allergic reaction or Anaphylaxis, Epinephrine should not be viewed as a sole treatment for the condition. These life-threatening conditions require immediate emergency medical attention and hospitalization. In the event that relief from symptoms is experienced after an Epinephrine injection, an emergency room should still be visited as soon as possible.

Extraordinary vigilance is required when using and caring for Epinephrine autoinjectors. They may not work properly if rough-handled or damaged. The injectors should be regularly inspected to ensure that the liquid within them have not changed color or have solid substance floating in the liquid. It is very important that the injectors only be used once and disposed of, not used again if there is a remaining portion. Keep the injector with the patient only until medical personnel arrives so that they know how many injections have been administered.

Proper use of this medication and proper monitoring of a patient who has received the injection is very important. The injection should only be administered into the muscle of the outer thigh. Failure to observe this guideline can cause tissue damage, especially if injected into extremities such as the hands or feet. If an accidental injection occurs, visit the emergency room immediately. A doctor should be immediately informed if there is any trouble with the injection site including numbness, swelling, redness, infection, pain, or a feeling of tenderness. Blood or urine tests may need to be administered after use of this medication as it has been known to affect blood sugar levels.

Epinephrine has interaction warnings with a significant number of medications, and thus all prescription and nonprescription medication that is taken should be reported to the prescribing physician as these may affect the decision to use Epinephrine in an emergency situation.

Storage

This medication should be securely stored and kept out of the reach of children when not needed. While one or two doses may need to be carried, this should be in a secure carrier or purse. It is important that the medication is regularly monitored and inspected for any damage to the autoinjector, change in liquid color, or solids floating in the liquid may make the medication unusable. If the medication is in any o these states or if it is expired it should no longer be maintained. Follow all guidelines for disposal of medical waste or ask your doctor if you have any questions regarding its disposition. When stored for long periods of time, care should be taken that the liquid is not allowed to freeze or boil. Keeping it away from both sources of heat and freezing temperatures should inform where to store it. Ideally, it should be stored at room temperature in the home, not in vehicles or outdoor areas. If the dose is dropped or otherwise impacted, inspect it to ensure that there is no damage or leakage from the autoinjector.

Summary

Epinephrine is a common hormone injection that has a wide degree of medical utility, but is best known as a constant companion for those with severe allergies. When used as an injection for the treatment of allergies and Anaphylaxis, Epinephrine is a very effective and fast-acting treatment that acts on the condition by spiking levels of adrenaline to help the body fight the allergic reaction. Immediate relief can include reduction of swelling, restoration of breathing airways, and equalization of blood pressure. In short, it can be the difference between life and death for patients with severe food allergies or insect stings. For this reason, it is an essential item constantly carried by patients who suffer from these severe allergic reactions. However, the injectors are also a fixture in emergency rooms that are often used as a last resort when patients are on the very brink of death from various traumas and are instrumental in restoring breathing and heartbeat.

Epinephrine is one of the most remarkable life-saving drugs on the market for the treatment of potentially lethal allergic reactions. In recent years, many controversies have risen as a result of questions of price and availability of this medication because of how vital it is to the survival of allergy sufferers. When it is used properly it can provide instant relief that allows those having a reaction to survive long enough to reach the emergency room. Although there are certain risks including accidental injection, potential abuse, or severe drug interactions there are very few options when it comes to emergency treatment for Anaphylaxis. So long as proper care is taken in educating those who carry these injectors in their proper use and the risks that improper use carries, Epinphrine will continue to be the best friend of allergy sufferers for years to come.