EpiPen Auto-Injector 300mcg Adrenaline

EpiPen general information

What is EpiPen used for?

EpiPen autoinjector is an emergency treatment for acute rapid and severe allergic reaction known as anaphylaxis or anaphylactic shock, which can be life-threatening if not treated. Anaphylaxis is a severe allergic reaction induced by an allergen, which is a substance that the immune system reacts to as a potential threat. The most common causes of anaphylaxis include some medicines like aspirin and penicillin; some foods like peanuts, shellfish and eggs; a bee or wasp sting, and latex. Anaphylaxis affects the whole body and symptoms develop within 5-30 minutes of exposure. They include, drop in blood pressure, increased heart rate, difficulty breathing and wheezing, swelling of the throat, tongue and face, abdominal pain, vomiting and diarrhoea, confusion and severe hives, which is an allergic reaction of the skin with raised patches or wheals. An allergen does not usually induce anaphylaxis on the first exposure, for example, the first bee or wasp sting, but once the immune system is sensitised, the allergic reaction is usually more severe on the next exposure, increasing risk of anaphylaxis occurring. Epi Pen autoinjector is a single use treatment that is administered by injection only and its effects are rapid to relieve life-threatening symptoms of anaphylaxis.

How does EpiPen work?

Epi-Pen autoinjector contains adrenaline (epinephrine) that is a naturally occurring hormone produced by the adrenal gland and also by certain nerve cells and is released in response to stress. Adrenaline in EpiPen autoinjector is used as a direct acting sympathomimetic drug, by acting as an adrenergic stimulant, which means it binds to adrenergic receptors and stimulates a specific response; it is also a vasopressor agent, which means it constricts blood vessels. Adrenaline has several physiological reactions including causing constriction and narrowing of blood vessels, increasing heart rate and widening air passages, all of which under normal conditions contribute to preparation for the “fight or flight” response. Anaphylaxis is a hypersensitivity reaction of the immune system and is caused by a sudden release of histamine from white blood cells including mast cells and basophils. Histamine is involved in allergic reactions by binding to the H1 receptor in small blood vessels causing them to dilate and widen and this allows leakage of fluid into the surrounding tissues, causing swelling. Adrenaline in EpiPen autoinjector binds to specific alpha adrenergic receptors on blood vessels walls causing them to constrict and become less permeable, which reduces swelling in the throat, face and skin; also beta adrenergic receptors on the bronchial smooth muscle of the airways, causing them to relax and widen, which reduces bronchospasm (narrowing of the airways) and helps return breathing to normal. Adrenaline is also a strong cardiac stimulant and helps return heart beat to normal, as well as increasing blood pressure. Other actions of adrenaline include relieving gastrointestinal symptoms by relaxing smooth muscle in the stomach. The action of adrenaline in EpiPen autoinjector is rapid and short-lived and helps relieve symptoms of anaphylaxis.

What does EpiPen contain?

EpiPen autoinjector contains the active ingredient adrenaline (epinephrine) (300mcg/0.3mL), an adrenergic agent that is used as emergency treatment for anaphylaxis. It also contains sodium chloride, sodium metabisulfite and hydrochloric acid.

Treating anaphylaxis with EpiPen

EpiPen autoinjector contains adrenaline (epinephrine) that is used as emergency treatment for anaphylaxis to relieve potentially life-threatening symptoms including, drop in blood pressure, increased heart rate, difficulty breathing and wheezing; swelling of the throat, tongue and face; abdominal pain, vomiting and diarrhoea; confusion; and severe hives (raised patches or wheals on the skin). Anaphylaxis is a hypersensitivity reaction of the immune system induced by various allergens, including medicines like aspirin and penicillin; some foods like peanuts, shellfish and eggs; a bee or wasp sting, and latex. It is caused by a sudden release of histamine from white blood cells like mast cells, which binds to receptors in blood vessel walls causing them to dilate and widen and this allows leakage of fluid into the surrounding tissues, causing swelling. Adrenaline in Epi-Pen autoinjector acts directly on blood vessels walls causing them to constrict and become less permeable, which reduces swelling in the throat, face and skin. It also acts on bronchial smooth muscle of the airways, causing them to relax and widen, which reduces bronchospasm (narrowing of the airways) and helps return breathing to normal. Adrenaline also acts directly on the heart and helps return heart beat to normal, as well as increasing blood pressure. These and other actions of adrenaline in Epi Pen autoinjector rapidly relieve serious life-threatening symptoms of anaphylaxis, when injected as soon as possible after the symptoms begin.

What are the side effects of EpiPen?

Since EpiPen autoinjector is used when symptoms of anaphylaxis are potentially life-threatening, side effects are relative. They do however, include, tachycardia (rapid heartbeat), difficulty breathing, dyspnoea (shortness of breath), dizziness, pallor (pale skin colour), fear, anxiety, restlessness, tremor, weakness, headache, nausea, vomiting, sleeplessness, cold extremities, sweating, hallucinations, palpitations, fear and flushing or redness of face and skin.

When should EpiPen not be used?

Note: Contraindications to using EpiPen autoinjector should not necessarily prevent its use as an emergency life-saving treatment.
EpiPen autoinjector should be administered with caution by anyone who:

• Has an allergy to any ingredients in EpiPen autoinjector
• Has high blood pressure or heart disease
• Has diabetes, thyroid disease or narrow-angle glaucoma (high pressure in the eye)
• Is having an anaesthetic
• Is taking medicines that interact with adrenaline in EpiPen autoinjector, including, some antidepressants including monoamine oxidase inhibitors and tricyclic antidepressants, thyroid hormone, some antihistamines like diphenhydramine, other sympathomimetic agent, ergot alkaloids for migraine, the local anaesthetic phentolamine, beta blockers like propanolol for heart conditions, some diabetic medications.
• Adrenaline is physically incompatible with alkalis, metals, oxidising agents, sodium warfarin, hyaluronidase and many other drugs; it forms polymers with sodium bicarbonate.

What medications interact with EpiPen?

Several medications interact with adrenaline (epinephrine) in EpiPen autoinjector but should not necessarily prevent its use as an emergency life-saving treatment.

• Drugs that cause a serious reaction with adrenaline in EpiPen autoinjector: other sympathomimetic agent, beta blockers like propanolol for heart conditions, some diabetic medications.
• Drugs that affect adrenaline in EpiPen autoinjector: some antidepressants including monoamine oxidase inhibitors and tricyclic antidepressants, thyroid hormone, some antihistamines like diphenhydramine, ergot alkaloids for migraine, the local anaesthetic phentolamine.
• Adrenaline is physically incompatible with alkalis, metals, oxidising agents, sodium warfarin, hyaluronidase and many other drugs; it forms polymers with sodium bicarbonate.

How should EpiPen be used?

EpiPen autoinjector should be carried by anyone at risk of anaphylaxis and used only if an anaphylactic reaction occurs. It should be used immediately you experience any symptoms of anaphylaxis, including, difficulty breathing, swelling in the face or throat, irregular pulse, hives, severe gastrointestinal problems like abdominal pain, vomiting and diarrhoea. You should know how to use the EpiPen autoinjector and follow the instructions for intramuscular injection. For adults greater than 30kg in weight the correct dose is a single injection of 300mcg injected into the muscle, usually the top outside thigh. It is important to avoid injecting into a blood vessel. You should seek medical assistance after using an EpiPen autoinjector.

How should EpiPen be stored?

You should store your EpiPen between 15 and 25°C in a cool dry place. Keep away from direct light and do not refrigerate.