Is the Needle Length on Epinephrine Auto-Injectors Too Short?
Image via Wikipedia Epinephrine is the first-line medication for the immediate treatment of anaphylaxis (sometimes referred to as "killer allergy"). Intramuscular injection of epinephrine is superior to subcutaneous injection in terms of how fast peak plasma levels of the life-saving drug are achieved. Consequently, epinephrine auto-injectors are deigned to deliver the medication to the large muscle of the anterior thigh (called the vastus lateralis). A recent study published in the July issue of the Journal of Pediatrics, however, suggests that intramuscular injection may not be achieved in a significant percentage of children with the current needle lengths of epinephrine auto-injectors (EpiPen and TwinJect). Ultrasound measurements of the thickness of subcutaneous tissue in children indicated that the needle lengths of the auto-injectors may be too short to penetrate into the muscle. When the outcome that one is attempting to prevent is death, this is no small issue.