Q:

Who or what group made the decision to make the minimum weight cut-off for the "junior" dose of EpiPen & generic epi auto-injector at 33 lbs?

 

I have read that infants, teenagers, and elderly are statistically more likely to die and/or have serious anaphylaxis, and I wonder if one of the reasons infants have severe anaphylaxis is, in-addition to the fact that an infant cannot talk and it can be harder to assess an infants (infant-medicine is like veterinary medicine in that sense): is one of the reasons why they are more likely to die because we DON'T HAVE HOME-USE epinephrine AUTO-INJECTORS to use on infants?

 

Essentially, I am wondering if one reason infants are more likely to die is due to the fact that the parent does not have a home-use epinephrine injector that is easy-to-use. If the weight limit were decreased from 33 lbs to 20-or-so pounds that would cover a lot more infants. On what actual science did whoever set the weight limit at 33 lbs based that cut-off on? Have their ever been any case reports of a child under 33 lbs being HARMED by any dose of IM or SC-administered epinephrine 1 mg/ml?

 

If an infant weighs 20 lbs and has had an anaphylactic reaction to cow's milk, should we write an rx for a multi-dose vial of epinephrine 1 mg/mL, which is inexpensive, and give it to the parent, along with syringes and needles, and have her practice drawing up 0.3 mL and injecting it into an orange?

A:

Thank you for your recent inquiry.

The fact of the matter is that the proper dose of epinephrine in either a child or an adult is totally unknown. The 0.01 mg per kg dosage is purely empirical. There are no pharmacokinetic, pharmacodynamic, or outcome studies of the dose response curve to epinephrine either in children or adults. Adverse events due to epinephrine overdoses have been recorded periodically in the literature, but they are more commonly reported in adults than children, and are due to errors of administration using a syringe and a multidose vial rather than an overdose to automatic injectors. In actuality children usually tolerate epinephrine quite well. It is better in most instances to prescribe an auto-injector than a syringe with a multidose vial in the instance you describe.

For more reading on this issue, I refer you to a recent editorial in the "Annals of Allergy, Asthma, and Immunology" (1).

Thank you again for your inquiry and we hope this response is helpful to you.

Reference:
1. Lieberman P. The 10 second rule and other myths about epinephrine and autoinjectors. Annals of Allergy, Asthma, and Immunology 2011 (September); 107(3):189-190.

Sincerely,
Phil Lieberman, M.D.

AAAAI - American Academy of Allergy Asthma & Immunology