Thursday, February 12, 2015

Throwback Drug Thursday: Sus-Phrine, An Aqueous Formulation of Epinephrine

Note: This is the introduction of a series of posts on Emergency Medicine PharmD called "Throwback Drug Thursdays" (#TBDT). It will feature medications that were once available for routine use in the emergency department, but are no longer on the market.  

I work with some awesome providers within my emergency department, many of whom have been practicing for quite some time. Sometimes, they will reminisce back to their time during residency, especially the interesting cases they encountered during their training. One day, we were talking about the management of status asthmaticus, and one of my physicians stated that during her residency, she routinely used a medication called Sus-Phrine, and described how efficacious it was in managing these patients. I mentioned that I never heard of any product called Sus-Phrine. Of course, I got teased (with reactions along the lines of “Finally! We stumped her on something!”), but I did a little digging, and was quite surprised to find out specific details related to this medication, which is none other than a rather interesting formulation of epinephrine.

Well, if you thought the concentrations of epinephrine in currently available formulations are prone to errors, as discussed in this post here and here, then it’s no small wonder how some people will react when they learn that this product existed in a concentration of 1:200. Yes, that’s right…1:200.

When the product was first introduced in the 1950s, one of its claims to fame in terms of administration was that as opposed to an intramuscular injection (such as the gluteal muscle) with a relatively large needle, as was the case for decades before this product was released, it could be administered subcutaneously with a needle of any gauge, including a tuberculin-type needle. 

Before Sus-Phrine made it to the market, epinephrine was commonly prepared in either peanut oil or gelatin, which posed many problems in terms of its preparation and administration. This was especially true in times of extreme cold weather where the product would often coagulate, which proved to be challenging when drawing up the product into a syringe for administration. The stability and pharmacokinetic properties of the product was more predictable due to the aqueous nature of the product (contained as a suspension made of phenol, sodium thioglycollate, and glycerin in distilled water).

Another one of the purported advantages of Sus-Phrine was the fact that its duration of action was generally six to ten hours, minimizing the need for repeat administration as was necessary for previous preparations of epinephrine. The onset of action following administration of Sus-Phrine occurred within 10 to 20 minutes.

The recommended dosing strategy of Sus-Phrine was a bit of a doozy as well: 0.005 mL/kg. Initial doses in pediatric and adult patients generally not exceeding 0.15 mL and 0.3 mL, respectively, which was somewhat convenient as the product was commercially available in a vial size of 0.3 mL. It was used as a therapeutic adjunct in the management of status asthmaticus, urticaria, and angioedema for quite some time, but production of Sus-Phrine discontinued in the early 1990s.  

Small wonder how practices related to managing such conditions as status asthmaticus and angioedema and formulations of epinephrine have evolved over the past several decades. It is a bit ironic how we have come full circle with epinephrine in terms of preferred route of administration, dosing, and duration of action with available formulations. It certainly makes me appreciate what we can learn all the more from those who are seasoned in practice. And I will never again be puzzled the next time I hear about Sus-Phrine in a conversation.


Naterman HL. Ephinephrine base suspended in water with thioglycolate. J Allergy 1953; 24:60.

Unger AH, Unger L. Prolonged epinephrine action. Ann Allergy 1952; 10:128-130.

Jenkins CM. A clinical study of Sus-Phrine, an aqueous epinephrine suspension for sustained action. J Natl Med Assoc 1953; 45:120-122.

Ben-Zvi Z, Lam C, Hoffman J, et al. An evaluation of the initial treatment of acute asthma. Pediatrics 1982; 70:348-353.

Ben-Zvi Z, Lam C, Spohn WA, et al. An evaluation of repeated injections of epinephrine for the initial treatment of acute asthma. Am Rev Respir Dis 1983; 127:101-105.

Kornberg AE, Zuckerman S, Welliver JR, et al. Effect of injected long-acting epinephrine in addition to aerosolized albuterol in the treatment of acute asthma in children. Pediatr Emerg Care 1991; 7:1-3.