Anaphylaxis and epinephrine prescribing patterns in a military hospital: underutilization of the intramuscular route

Epinephrine is the only definitive treatment of anaphylaxis, and recent evidence suggests that the intramuscular route has superior pharmacokinetics to subcutaneous administration. There is little data regarding what route is commonly used in clinical practice. The objective of this article is to determine the rate of epinephrine use in cases of anaphylaxis and route of administration utilized. A retrospective review was made of 220 medical records with the primary diagnosis of urticaria, angioedema, or anaphylaxis over a 28-month period at a military medical center. Twenty-four cases of anaphylaxis identified in the records. Demographics, along with signs and symptoms of those experiencing anaphylaxis, were similar to other published reports. Epinephrine was given in only 50% of cases and largely by the subcutaneous route. No intramuscular epinephrine was administered. H1 blockers and steroids were the most commonly administered treatments. H2 blockers were given at the same rate as epinephrine. An autoinjector was prescribed in 29% of cases with instruction on its use documented in 13%. An allergy referral was made in 29% of cases. Greater educational efforts and collaboration are needed between the allergy community and other providers regarding the importance of administering epinephrine intramuscularly, prescribing autoinjectors, and referring to an allergist in cases of anaphylaxis.