Author: Bryan G. Kane, MD, FACEP, Associate Professor of Medicine, University of South Florida Morsani College of Medicine; Assistant Program Director (Research), Lehigh Valley Health Network Emergency Medicine Residency
With the onslaught of COVID-19, emergency physicians will unfortunately need to cope with shortages of medications.1 One such shortage is albuterol, specifically metered-dose inhalers (MDIs).2 MDIs are preferred with COVID-19, as they have decreased aerosolization of the virus compared to nebulized delivery.3 Should emergency physicians wish to order bronchodilators without the risk of aerosolization, there are studies of intramuscular (IM) options in the literature.
Terbutaline is a beta-2 agonist that can be used to treat asthma.4 There are several publications that address the use of terbutaline in acute bronchospasm. When administered subcutaneously, terbutaline results in clinical improvement similar to epinephrine.5,6,7 One study noted a slightly higher rate of tachycardia in injected terbutaline versus injected epinephrine.8 Focusing on acute, rather than chronic, use of terbutaline, a prospective study did not find elevations in troponin.9 This small cohort of 29 critically ill children did note ECG changes during intravenous (IV) infusions. The Chiang study was one of three studies included in a 2017 systematic review on the safety of pediatric asthma medications.10 This review identified 14,560 citations, included 46 randomized controlled trials, and found a total of 11 reported adverse drug reactions with terbutaline (4 with IV infusion and 7 with PO administration). No adverse drug events were identified with subcutaneous injection. When treating adults, a 1988 study of 108 asthmatics ages 18 to 96 did not identify a relationship between age and ventricular dysrhythmia when treated with subcutaneous epinephrine (0.3 mg 1:1000).11
Based on available evidence, injected terbutaline or epinephrine appears to be a viable alternative to nebulized bronchodilators for acute asthma exacerbations during the COVID pandemic. It should be noted that the subcutaneous terbutaline injection site used in the studies noted here is the deltoid. For adults, IM injection of epinephrine in the thigh has been demonstrated to lead to significantly higher peak plasma levels as compared to IM or subcutaneous injection in the upper extremity.12 The superiority of IM injection over subcutaneous injection for epinephrine has also been demonstrated in children.13 In one study from 1974, terbutaline was administered IM.14 In this crossover study of 20, 7 patients had side effects such as tremor or restlessness after terbutaline. Recommended dosing of terbutaline for asthma varies from 0.25 to 0.5 mg subcutaneously in the deltoid. The dosage of epinephrine varies in the studies noted. One advantage of using 0.3 mg of 1:1000 epinephrine (0.15 mg for pediatrics) is staff familiarity with this dosage due to its usage in the treatment of anaphylaxis.
Critical Issues in the Management of Adult Patients Presenting With Community-Acquired Pneumonia