From the Guidelines
Yes, an epinephrine (adrenaline) nebulizer can affect serum epinephrine levels, though the effect is typically less pronounced than with injected epinephrine. When administered via nebulization, epinephrine is primarily intended to work locally in the airways to reduce bronchospasm and mucosal edema through its bronchodilatory and anti-inflammatory effects. However, some systemic absorption does occur through the respiratory mucosa and alveoli. The standard dosing for nebulized epinephrine is typically 2.25% racemic epinephrine solution (0.5 mL in 3 mL saline) or 1:1000 (1 mg/mL) L-epinephrine solution (0.5 mL in 3 mL saline), administered every 1-4 hours as needed, as seen in the guidelines for treating severe asthma exacerbation or laryngotracheobronchitis (croup) 1. The systemic effects are generally less significant than with intramuscular or intravenous administration because the total dose absorbed is lower and absorption is more gradual. Patients with cardiovascular conditions should be monitored for potential side effects like tachycardia, hypertension, or arrhythmias, as these may indicate significant systemic absorption, as noted in the context of cardiogenic shock, congestive heart failure, or anaphylaxis treatment 1. The clinical significance of these serum level changes varies by patient and is generally more relevant in those with underlying cardiovascular disease. It's also worth noting that while the primary studies provided do not directly address the impact of nebulized epinephrine on serum levels, the pharmacological properties of epinephrine and its known effects when administered via different routes support the conclusion that nebulized epinephrine can lead to some increase in serum epinephrine levels, albeit typically less pronounced than with injectable forms 1.
From the FDA Drug Label
Directions The ingredient is used in an aqueous solution at a concentration equivalent to 1 percent epinephrine. The FDA drug label does not answer the question.
From the Research
Effect of Epinephrine Nebulizer on Serum Epinephrine Levels
- The use of an epinephrine nebulizer can potentially affect serum epinephrine levels, as evidenced by studies on the systemic absorption of epinephrine via different routes of administration 2, 3.
- A study on intranasal epinephrine administration found that significant systemic absorption of epinephrine occurred only at a dose of 5 mg, which was comparable to intramuscular epinephrine administration 2.
- Another study comparing intranasal and intramuscular routes of epinephrine administration found that intranasal epinephrine absorption was about 0.5-fold that of intramuscular epinephrine, but the difference was not statistically significant 3.
- However, it is essential to note that the studies mentioned above focused on intranasal administration, and the effects of nebulized epinephrine on serum levels may differ.
- There is limited direct evidence on the impact of epinephrine nebulizers on serum epinephrine levels, but a study on the response to nonprescription epinephrine inhaler during nocturnal asthma found that epinephrine was nearly as effective as albuterol in terminating an acute episode of airway obstruction without significant cardiovascular effects 4.
- Additionally, a case report on the use of nebulized racemic epinephrine in the treatment of severe asthmatic exacerbation did not provide information on the effects on serum epinephrine levels 5.
- Another case report on life-threatening cardiac arrhythmia after a single dose of nebulized epinephrine in a pediatric emergency department highlighted the potential risks associated with nebulized epinephrine therapy, but did not discuss serum epinephrine levels 6.