Date Published

September 29, 2016

Updated For

ALS PCS Version ALS PCS Version 5.2


Question: I know that the standard practice for Epinephrine administration in the case of anaphylaxis is in the patient's deltoid. I have heard and read that the time to maximal serum concentration of epinephrine is 7 times faster with IM administration to the anterolateral thigh.

My question therefore is: Would it be acceptable to administer epinephrine in the anterolateral thigh as opposed to the deltoid? Or, is SWORBHPs preferred administration site the deltoid and if so why?


Simmons, F.E., Kelso J.M., Feldweg A.M. (2015). Anaphylaxis: Rapid recognition and treatment. In T. W. Post (Ed.), UpToDate. Retrieved from


 You are correct in that there are proponents for Deltoid IM injection in Anaphylaxis.  Proponents of the deltoid route include the American Academy of Allergy Asthma and Immunology (AAAI).  This is based on a study examining 13 men to determine when the peak plasma level of epinephrine was reached (not when its targeted action was achieved).  However, as a whole, the most consistent and safe IM route is via the deltoid due to todays increasingly adipose-rich population.  In fact, a study done examining the EpiPen auto injector (needle length of 1.43cm) found that 42% of the female sample population studied would not be able to reach their IM compartment.  Yes, subcutaneous administration will also produce an effect, but much slower than IM due to its less-rich blood supply.  Thus, it is base hospitals recommendation to keep the preferred site of IM Epi injection as the deltoid.


Kemp SF, Lockey RF, Simons FE, the World Allergy Organization ad hoc Committee on Epinephrine in Anaphylaxis.Epinephrine: The drug of choice for anaphylaxis€”a statement of the world allergy organization.  World Allergy Organ J. 2008 July;1(2):18-26.

Chowdhury BA, Meyer RJ. Intramuscular versus subcutaneous injection of epinephrine in the treatment of anaphylaxis. J Allergy Clin Immunol.2002;1:720€“721. IV

Sheikh A, Shehata YA, Brown SGA, Simons FER (2009). Adrenaline (epinephrine) for the treatment of anaphylaxis with and without shock (systematic review). Cochrane Library 2009, Issue 1

Simons FER, Roberts JR, Gu X, Simons KJ. Epinephrine absorption in children with a history of anaphylaxis. J Allergy Clin Immunol. 1998;1:33€“37. doi: 10.1016/S0091-6749(98)70190-3. IIa

Simons FER, Gu X, Simons KJ. Epinephrine absorption in adults: Intramuscular versus subcutaneous injection. J Allergy Clin Immunol.2001;1:871€“873. doi: 10.1067/mai.2001.119409. IIa

Song TT, Nelson MR, Chang JH. et al. Adequacy of the epinephrine autoinjector needle length in delivering epinephrine to the intramuscular tissues. Ann Allergy Asthma Immunol. 2005;1:539€“542. doi: 10.1016/S1081-1206(10)61130-1. III

Zuckerman JN. The importance of injecting vaccines into muscle: different patients need different needle sizes. BMJ. 2000;1:1237€“1238. doi: 10.1136/bmj.321.7271.1237. IV



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