Epinephrine (or adrenaline) is used to treat anaphylaxis, a severe allergic reaction to peanuts, bee stings, and other allergens. Found in the EpiPen and Twinject auto-injector medications, epinephrine opens airways in the lungs, narrows blood vessels, and otherwise counteracts the symptoms of a severe allergic reaction.
Auto-injectors, which are commonly kept on hand for self-injection by those with severe allergies, contain between 0.15 and 0.5 mg of epinephrine. The effects of the injection usually wear off within 10 to 20 minutes. Patients are advised to seek immediate medical attention within this timeframe.
To avoid the risk of an overdose, do not repeat doses of epinephrine without contacting a doctor. Overdosing on epinephrine is more likely if a second auto-injector is used to treat the same reaction. If the person with a severe allergy is a child, it is important to use an auto-injector designed for use on children, which usually contains 0.15mg of epinephrine as opposed to the 0.3mg dose contained in many auto-injectors meant for adult use.
An overdose of epinephrine can cause dangerously high blood pressure, accompanied by effects such as severe headache, blurred vision, anxiety or confusion, chest pain, fast or uneven heartbeats, sudden weakness or numbness, and shortness of breath. Patients who have received too much epinephrine may feel like they might pass out or experience sudden problems with speech or balance. If any of these symptoms occur, it is important to obtain prompt medical attention, both for treatment of the allergic reaction requiring the use of epinephrine and to treat the overdose.