In the past week I’ve been surprised to learn that there is a surprising number of choices available to the prescribing pharmacist.  I’ve been watching a discussion thread on Kids with Food Allergies, and hadn’t heard enough yet (or done enough legwork yet) to pass along any meaningful information.  However a recent post on our yahoo forum and FB page prompted me to spend some time researching the issue at hand.  I will try to annotate sources as I go so you can read further if desired.

There are currently 4 auto-injectors in the marketplace.
  •  Epi-pen™ is produced by Mylan Industries wholly owned subsidiary Dey Pharma, L.P.    Epi-pen™ is available in two dosage strengths, prescribed by body weight.  There is no generic Epi-pen™ because it is a trademarked name brand.  In Canada it is distributed by King Pharmaceuticals, a wholly owned subsidiary of Dey Pharma
                 Drugs.com product info on Epi-pen™
  •  Twinject™ is produced by Shionogi Pharma (formerly Sciele).  Twinject™ is the only autoinjector with 2 doses of epinephrine available.  Twinject™ is available in two dosage strengths, prescribed by body weight.  There is no generic Twinject™ because it is a trademarked name brand.
                Drugs.com product info on Twinject™
  • Adrenaclick™ is also produced by Shionogi Pharma’s indirect wholly owned subsidiary, Sciele Pharma, Inc.  Adrenaclick™ provides a single dose of epinephrine, and is available in two dosage strengths, prescribed by body weight. 
             FDA product insert information for Adrenaclick™
             Shionogi Pharma January press release announcing the Adrenaclick™ product,
             Sciele January news release
             Drugs.com product information on Adrenaclick™
  •  FDA authorized generic Greenstone Epinephrine autoinjector.  Shionogi Pharma has given Pfizer’s wholly owned subsidiary Greenstone permission to market the Adrenaclick™ product as an FDA authorized generic.  An FDA authorized generic allows both companies to compete, where an FDA approved generic is for a product on which the patent limits have met.*   This product is being called “Epinephrine auto-injector” and you may receive this as a generic, depending on your prescription, pharmacy, and insurance plan. 
                 Drugs.com product info
                 DailyMed (NIH) product info

*My source of information on FDA authorized versus FDA approved generics

The AAAIII put out a statement just last week regarding this varied choices available.

The field of available epinephrine auto-injectors may continue to change.  After all this reading and researching, I've realized that I take epi-pen for granted and hadn't considered the impact of the fragility of the manufacturing, marketing, and sales chain on the form in which epinephrine auto-injectors are presented to the consumer.

In addition to auto-injectors, there are also several companies that market pre-filled epinephrine syringes (some considered generics) which used to be the standard before auto-injectors.  A few sites I visited suggested that this might be an elegant low-cost alternative to auto-injectors.  Please stay informed of your choices and ask questions of your allergist and pharmacist as you fill those prescriptions!

Other resources:
Pharmacist discussion topic on epinephrine auto-injector substitution
Kids with Food Allergies discussion thread on New York Times article referring to Adrenaclick and its authorized generic.
Kids with Food Allergies discussion thread from member who received Greenstone auto-injectors.

Please reply via comment or email with any further information or experience you have to benefit all our members!