When injected intramuscularly, epinephrine takes just five minutes to work, making it much faster than other emergency medications such as antihistamines (which take at least 30 minutes) and glucocorticoids (which take around 60 minutes).

In cases of severe anaphylactic reaction, the intramuscular administration of epinephrine “is the best choice”, said Tobias Ankermann of the University Medical Center Schleswig-Holstein in Kiel during the German Allergy Congress. It is easy to perform and quickly achieves the desired effect.
There are a number of other alternatives to intramuscular administration.

Intravenous administration: too time consuming

Epinephrine can be administered intravenously in a hospital setting. However, the time required for administration is often underestimated. Even skilled professionals need at least three minutes to prepare the syringe and inject it, said Ankermann.

Epinephrine inhalation: not an alternative

There is also a special epinephrine preparation that can be inhaled. The active ingredient is then absorbed through the pulmonary capillaries. However, Ankermann expressed doubts as to whether it would have a sufficient effect on the circulation when administered via this pathway. Although the drug was detected in blood, the blood pressure remained almost unchanged (Breuer 2013). “Epinephrine inhalation is an option, but it is not an alternative to injection.”

Sublingual epinephrine in the future?

When medicines are administered sublingually (‘under the tongue’), the active ingredient is mainly absorbed through the thin mucous membrane under the tongue. A study from 2015 revealed that this principle can also work with epinephrine in the form of microcrystals (Rawas-Qualaji 2015). However, since it takes at least one hour to start working, this method is not an alternative to intramuscular administration at this stage of development.

Epinephrine (adrenaline) is critical in the treatment of anaphylactic reactions. It narrows the enlarged blood vessels, reduces their permeability and can relieve the tightening of the bronchial muscles (bronchospasms).

Sources

Dt. Allergiekongress 2019. Therapie in der Anaphylaxie – Unterschiedliche Applikationswege. Vortrag von Tobias Ankermann, Klinik für Kinder- und Jugendmedizin I, Universitätsklinikum Schleswig-Holstein, Campus Kiel

Breuer C et al. Pharmacokinetics and pharmacodynamics of moist inhalation epinephrine using a mobile inhaler. Eur J Clin Pharmacol. 2013;69(6):1303-10

Rawas-Qalaji M et al. Sublingual Diffusion of Epinephrine Microcrystals from Rapidly Disintegrating Tablets for the Potential First-Aid Treatment of Anaphylaxis: In Vitro and Ex Vivo Study. AAPS PharmSciTech 2015;16(5):1203–12

Text: mh/ktg