Epinephrine Autoinjector Use One Year after Training: A Randomised Controlled Comparison of Two Different Devices
Monday, February 23, 2015
Exhibit Hall A3 (Convention Center)
Robert J. Boyle, MBChB PhD, Annabella Procktor, PhD, Matthew Hodes, Jared G Smith, Claudia Gore, MD, Helen E. Cox, FRCPCHMD, Paul J. Turner, FRACP PhD, Tom Marrs, MD, Heather Hanna, RN MSc, Katherine Phillips, RGN, John O. Warner, MD, Camila Pinto, BSc, Thisayanagam Umasunthar, MD
Rationale: Previous cross-sectional studies found patients have poor understanding of how to use epinephrine autoinjectors (EAI). We tested whether prescribing different EAI devices affected patients' ability to administer epinephrine 1 year after training.

Methods: We randomly allocated 158 mothers of food-allergic children prescribed an EAI for the first time, to Anapen or Epipen with appropriate training. Treatment was allocated by a third party using a computer-generated randomisation sequence. The primary outcome, ability to effectively administer epinephrine in a recorded simulated anaphylaxis scenario, was assessed by a paediatric allergist independent of the trial and host institution. ISRCTN12504076

Results: We evaluated ability to administer epinephrine at 1 year in 110/158 (70%) randomised participants. Overall success rates were low, and similar between the 2 groups - 28/51 (55%) using Anapen, and 35/59 (59%) using Epipen (P=0.64). The primary reason for failure differed between groups (P<0.001). Failure to remove all safety caps was most common for Anapen (33%); using the wrong end of the device for Epipen (17%). When actual device-specific epinephrine delivery times were taken into account, success rates were 30/51 (59%) for Anapen and 42/59 (71%) for Epipen (P=0.17). Digital injection - the only adverse event recorded – occurred in 8/59 (14%) in the Epipen group, and 0/51 (0%) in the Anapen group (P=0.007).

Conclusions: EAI success rates were similar for Anapen and Epipen 1 year after training, but digital injection was more common with Epipen. Optimal EAI design should include a single safety cap, and easy identification of the needle end.