Key words
Introduction
Simons KJ, Simons FER. Epinephrine and its use in anaphylaxis: current issues. Epinephrine auto-injectors for anaphylaxis in community settingshttp://www.medscape.com/viewarticle/726456_4. Accessed April 17, 2012.
Review of Epinephrine and Administration Devices
Simons KJ, Simons FER. Epinephrine and its use in anaphylaxis: current issues. Epinephrine auto-injectors for anaphylaxis in community settingshttp://www.medscape.com/viewarticle/726456_4. Accessed April 17, 2012.

Meda. EpiPenhttp://www.epipen.co.uk. Accessed May 3, 2012.




Accessing Epinephrine From Post-2010 EpiPens

WMO Method
- •This removal method starts by making a 1.25-inch cut in the center of both flat sides, starting at the end with the blue safety cap and moving toward the needle (Figure 7).Figure 7Demonstration of site to initiate cutting using the WMO method on a post-2010 EpiPen. Still photograph courtesy of Seth C. Hawkins, from video courtesy of David Fitzpatrick and Caleb S. Varnadoe.
- •Pliers can now wiggle and remove the white plastic end plug. This can be done by firmly holding the device and placing 1 nose of the pliers into the hole in the center of the white plastic end plug and grasping the outside of the device with the other nose of the pliers (Figure 8). Do not peel back the cut flaps of the rear end more than 50% or you will risk deploying the spring with uncontrolled force (Figure 9).Figure 8Pry back sheath less than 50%. Photo credits: Caleb S. Varnadoe, David Fitzpatrick.Figure 9Tools used to remove the carpule, the carpule itself after removal, and the opened auto-injector shell of a post-2010 EpiPen. Photograph courtesy F. Baty.
- •Pulling and wiggling frees the spring assembly from the case, allowing the spring to expand in a controlled fashion and causing the white end plug to be pushed out of the housing with the spring (Figure 10). The syringe can now be pulled out.Figure 10Pliers grip rear of unit. Photo credits: Caleb S. Varnadoe and David Fitzpatrick.
Roane State Method
- •This removal method involves releasing the top by cutting the translucent plastic cover between the white plastic triangles of the spring assembly and the spring end of the cover. Care must be taken when the spring is released, as the stored energy represents a significant force. An article of clothing, a sleeping bag, or other material should be placed near the end of the auto-injector to blunt any unexpected release.
- •Peel off the plastic cover that contains the instructions for the device’s use and begin cutting the plastic housing.
- •As the plastic housing is cut, it will eventually start to shift, meaning the spring mechanism is nearly free from the housing. When it does finally break free (Figure 5), the spring will launch the housing with some force.
- •Once the housing is off, the process is the same as with the first technique.
- •With the spring mechanism removed, turn the housing so the orange flat end is against the hard surface and push, allowing the carpule assembly to fall out of the housing (Figure 11).Figure 11Push the injector unit out against a solid object. Photo credits: Caleb S. Varnadoe, David Fitzpatrick.
- •To remove the carpule from the orange assembly, it must be released from the orange plastic. There are 2 long slots, 1 on each side of the assembly. In each narrow slot is a white plastic arm. These arms hold the carpule firmly in the assembly. Pinching over the white arms allows the carpule to slide out easily (Figure 12).Figure 12Plastic “wings” on each side of the injector unit must be depressed to release the unit. Photo credits: Caleb S. Varnadoe, David Fitzpatrick.
- •Looking at the open end, the one away from the needle, there will be 2 cylinders connected by a male-female arrangement: the one is white (with the male end), the other is black (housing the female connection). Separate these 2 cylinders. This must be done carefully to avoid spilling the epinephrine. Figure 9, Figure 13 demonstrate the carpule removed from the opened auto-injector shell.Figure 13Note air bubbles forming in syringe, and black plunger at edge of glass. That would be the appearance after plunger is drawn back to administer additional doses. An unused EpiPen would also have this appearance (black at end of glass, white entirely outside of glass) but would not have air bubbles in the carpule. Photograph courtesy F. Baty.
- •The carpule and its attached needle can now be used to administer additional doses of medication (see “Administering Additional Epinephrine” section below).
Accessing Additional Epinephrine From Pre-2010 EpiPens
WMO Method
- •After the device has been fired, hold it firmly on a hard surface with a fist around the body of the tube.
- •Position the end originally holding the gray safety cap over the surface edge.
- •Firmly grip the safety end with pliers and bend it down as if to snap it out of the tube.
- •Repeat this firm up-and-down movement several times and the spring and end plug will be released.
Roane State Method
- •In a wilderness setting, a knife may be more readily available than pliers. If a knife is the only tool available, the technique can be modified to use it.
- •First make sure the device has been fired, which is confirmed by seeing the exposed needle.
- •Remove the outer label. The interior components of the device are now visible through the translucent housing. This gives a reference point for the location of the cut to make on the device’s body. The carpule containing epinephrine can be seen, and to the rear of that is the plunger and plastic spring housing, which remains under tension after discharge.
- •Cut the translucent outer plastic case over the white spring housing, taking care to aim the spring-loaded end into a suitable surface such as a rolled sleeping bag or jacket. Once the body is cut to the point where it no longer contains the tension, the spring will deploy, ejecting the end of the device.
- •The spring is released by either the Roane State method or WMO method.
- •After removal of the spring, the carpule of epinephrine can be gently released by gravity when the remaining shell is turned needle up.
- •At the rear of the carpule is a rubber plunger, which is moveable. Remove carpule by gently pulling brass plunger fittings.
- •Carefully turn rubber needle proctor to loosen and remove. Point needle straight up, pulling carefully so as not to pull rubber out of the glass barrel tube until the rubber plunger is close to the end of the glass barrel, replacing the injected epinephrine with an air bubble. Be careful, because pulling the rubber plunger all the way will allow the epinephrine to be spilled and lost.
- •The carpule and its attached needle can then be used to administer additional doses of medication (see the “Administering Additional Epinephrine” section below for instructions).
Accessing Epinephrine From Other Auto-Injectors
- •Hold red needle end while injector body is unscrewed 2 and a half turns. Holding the red needle end while turning the body seems to minimize possibility of accidental needlestick.
- •Once the red cap and spring are free, lift them off and set aside.
- •Withdraw the blue needle hub with syringe from injector body. Look at where the rubber plunger is in the glass tube and mark (or take mental note if marking is not feasible).
- •Remove yellow or orange (older models) clip from plunger end to access second dose (Figure 4).
- •Additional doses require pointing the needle straight up and pulling the plunger back down to the end of the glass, drawing in more air. Reverse the syringe until the needle points straight down toward the thigh. The bubble of air will act as an auxiliary plunger/pusher.
Administering Additional Epinephrine Retrieved From Auto-Injectors

Method 1
- •Raising the needle into an upward position, draw enough air into the syringe to allow the plunger to return to its original position with the first edge of the black plunger just even with the end of the glass (Figure 15). This will introduce air into the carpule (Figure 13).Figure 15Carpule in place ready for injection shows air bubble above the fluid line. Here, cardboard is simulating the subject's injection site. Photo credits: Caleb S. Varnadoe, David Fitzpatrick.
- •Inject, pushing the plunger until it is stopped by the glass. This ensures the correct dose of the drug will be injected. Subsequent doses can be delivered in a similar manner.
Method 2
- •Lever the white component of the plunger out of the syringe (being careful not to dislodge the black part of the plunger).
- •Turn the white component of the plunger around 180°, insert it into the carpule, and inject in a more traditional manner.
Wilderness EMS Adaptations for Auto-Injectors
Conclusions
Disclaimers
Acknowledgments
Supplementary data
References
- Second symposium on the definition and management of anaphylaxis: summary report—Second National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network Symposium.J Allergy Clin Immunol. 2006; 117: 391-397
- Wilderness Medical Society roundtable report: recommendations on the use of epinephrine in outdoor education and wilderness settings.Wilderness Environ Med. 2010; 21: 185-187
Simons KJ, Simons FER. Epinephrine and its use in anaphylaxis: current issues. Epinephrine auto-injectors for anaphylaxis in community settingshttp://www.medscape.com/viewarticle/726456_4. Accessed April 17, 2012.
- Quandaries in prescribing an emergency action plan and self-injectable epinephrine for first-aid management of anaphylaxis in the community.J Allergy Clin Immunol. 2005; 115: 575-583
- Managing anaphylaxis in a jungle environment.Wilderness Environ Med. 2012; 23: 51-55
- Biphasic anaphylaxis: review of incidence, clinical predictors, and observation recommendations.Immunol Allergy Clin North Am. 2007; 27: 309-326
- Standards for Medical Oversight and Data Collection: EMS Protocols. Protocol 16: Allergic Reactions.North Carolina Office of EMS, Raleigh, NC2009
- Outdated EpiPen and EpiPen Jr autoinjectors: past their prime?.J Allergy Clin Immunol. 2000; 105: 1025-1030
Meda. EpiPenhttp://www.epipen.co.uk. Accessed May 3, 2012.
- Twinject Module 2: Twinject.Verus Pharmaceuticals, San Diego, CA2007 (31)
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- Regarding the Use of Epinephrine Auto-injectors in Remote SettingsWilderness & Environmental MedicineVol. 25Issue 4
- PreviewWe read with interest the recent article by Hawkins et al,1 entitled “Retrieval of additional epinephrine from auto-injectors.” The EpiPen and EpiPen Jr auto-injectors are distributed by Mylan Specialty L.P., formerly known as Dey Pharma. The company wishes to clarify a few statements in the article that are outdated or outside of product labeling approved by the US Food and Drug Administration (FDA).
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