O kay, so you’ve had a frighteningly severe allergic reaction -- say, to a bee sting or shellfish, both fairly common allergies -- and your doctor has given you a prescription for an EpiPen or another type of auto-injector, just in case. Do you know how to use it?

Auto-injectors are not difficult to operate but you don’t want to be fumbling around trying to figure it out when your eyes and throat are swelling up and you’re having difficulty breathing. Researchers have found an increase in errors in the use of auto-injectors over the past six years. That seemed to be a good reason to review their proper use, so I consulted Jay M. Portnoy, MD, chief of the section of allergy, asthma & immunology at Children’s Mercy Hospitals & Clinics in Kansas City, Missouri, and the immediate past president of the American College of Allergy, Asthma & Immunology (ACAAI).

WHAT GOES WRONG?

In a recent study, doctors at several universities took a collective look at the existing literature on the problem -- accidental sticks from auto-injectors. After reviewing 26 reports published in peer-reviewed journals over the past 20 years, they found that although errors are rare...

• Accidental sticks may occur if the device is used backward, causing the needle to pierce the thumb rather than the thigh, where the injection should be given. Not only does this hurt, it means the epinephrine won’t be released readily into circulation as intended.

• Ninety-one percent of people accidentally stuck their thumb or other finger.

• Over 65% of those who made mistakes with the devices visited emergency rooms.
  

There were no lasting injuries. Study results were published in the April 2009 issue of the Annals of Allergy, Asthma & Immunology.

CORRECT USE OF AUTO-INJECTORS

If you have been prescribed an automatic injection device such as an EpiPen (www.epipen.com) or Twinject (www.twinject.com), it’s important to know how to use it quickly and efficiently -- before you face an emergency. Your doctor or nurse should describe the process, clearly explaining how it should work. Note: Both Twinject and EpiPen come with a demonstrator or trainer, so you can practice using the device before you ever need it.

To correctly use an EpiPen, the most commonly prescribed device...

• Unscrew the cap from the carrying case and remove the auto-injector from its storage tube.

• Grasp the unit so that the black tip points downward. Hold the device in your hand, making a fist around the center of it.

• Use your other hand to remove the gray safety cap.

• Hold the device so the black tip is near the outer thigh, being careful not to touch it (doing so can trigger the needle) so you don’t accidentally activate it prematurely. You can either swing the device away to give yourself some momentum before jabbing your outer thigh or with Twinject you hold it firmly against your thigh and push. Either way, you’ll hear a "pop" when the epinephrine ampule breaks and the drug is released into your system. It is fine to give the injection through clothing.

• Continue to hold injector tight against the thigh, keeping the needle in your leg for a full 10 seconds to ensure that the entire dose is delivered. Though you’ll still see some liquid remaining, you will know the entire dose has been delivered when the window on the auto-injector turns red.

• Pull the injector straight out from your thigh and massage the injection area for 10 seconds. It’s a good idea to lie down and if you are feeling faint, put your legs above your head so that blood goes to the brain.

• For disposal, Dr. Portnoy counsels patients to bend the used needle by pressing it against a hard surface -- this protects from accidental needle sticks. Replace it carefully in the original carrying case and bring it to your doctor’s office or the hospital for safe disposal. Do not throw it in the trash, as it is now a biohazard.

• Store auto-injectors at room temperature. Avoid exposing them to extreme hot or cold conditions, such as the glove compartment of the car. Replace by the marked expiration date. Auto-injectors typically last 12 months. If you purchase one that has a shorter expiration date, point it out to your pharmacist and ask for a newer one. Though auto-injectors are expensive, most insurance plans pay for them.

KEEP IT TOGETHER

In about 30% of cases, people end up requiring a second injection to control their allergic reaction -- many, therefore, are packaged with two doses in one unit (Twinject) or two units per package (EpiPen). Dr. Portnoy advises keeping them together. Since you can still experience an intense reaction when the drug wears off, even after a second dose, Dr. Portnoy recommends seeing your doctor or visiting an urgent care center or emergency room after self-injecting epinephrine.