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Allergies: When to Use Your Auto-Injector

You can’t predict allergic reactions. They can be mild one time and serious the next. An attack can quickly become intense, sometimes leading to anaphylaxis -- a severe, often life-threatening reaction. An auto-injector -- such as EpiPen, Twinject, or Auvi-Q -- can treat extreme allergic reactions with an early, life-saving dose of epinephrine.

Epinephrine is adrenaline, a hormone your body naturally produces. Among other things, it can help improve breathing, raise blood pressure that’s dropping, and reduce swelling.

When you or a loved one has an allergic reaction, it’s common to wonder if the shot is needed. Experts say if there's any doubt, use the device. It’s much more dangerous not to get epinephrine when you’re having a severe reaction than to get a dose you don’t really need.

Keep the Injector Handy and Ready

The device won't do you any good if you don't have it with you. When you pick up your prescription at the drugstore, you'll get two injectors. Carry both with you at all times in case one doesn’t work or you have a reaction that requires more medication.

Extreme heat and cold can cause the medication not to work, so store devices at room temperature. Don’t leave them in your car.

The injectors are usually good for a year, so keep track of the date on the box.

When to Take the Shot

There are many cases when you, or someone you know, would need to use the auto-injector, but two general ones are:

1) If you have a life-threatening allergy and you know you’ve been exposed. An example: If you have a peanut allergy and your boyfriend ate some peanuts and then kissed you, don't wait for symptoms -- take the epinephrine right away.

2) If you're experiencing allergy symptoms -- even if you don’t know the trigger.

Those symptoms can include:

  • Difficulty breathing, wheezing, airways shutting down
  • Swelling of face, mouth, lips, tongue
  • Skin reactions like hives, itching, flushing
  • Nausea, stomach pain, vomiting, diarrhea
  • Dizziness, fainting, collapsing


What to Do After a Shot

Take these steps after the first injection:

  • If there's no relief, take a second dose. You could wait as few as 5 minutes for a severe reaction or 15 minutes if it is mild .
  • Have someone call 911.
  • Massage the injection site for 10 seconds to stimulate blood vessels and help the body absorb the medication. 
  • Go to the emergency room after an injection, even if symptoms improve or seem to go away. Severe episodes can last 4 to 12 hours, and you never know at the beginning how long yours will last.


Create a Plan

The common side effects from the epinephrine injection are dizziness, restlessness, anxiety, and shakiness. In rare cases, they may be more severe.

Work with the doctor to create a personalized response plan that outlines when you or your loved one needs to have an injection, and how to recognize signs of a severe allergic reaction. Your doctor will consider your age and any other medical issues you may have.

Share the plan with anyone who might have to use the injector on you or your loved one. That includes spouses, co-workers, teachers, school nurses, baby sitters, grandparents, etc.

Practice using the device. Check online for safety videos and updates. And make sure anyone who may have to use it knows how.

WebMD Medical Reference

Reviewed by Brunilda Nazario, MD on February 04, 2014
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