What are the contraindications for administering epinephrine (Epi) in cases of anaphylaxis?

From the Guidelines

There are no absolute contraindications for administering epinephrine in cases of anaphylaxis, and it should be given immediately when anaphylaxis is suspected, even in patients with cardiac disease, hypertension, or those taking medications that might interact with epinephrine. The risk of untreated anaphylaxis far outweighs the potential risks associated with epinephrine administration, as highlighted in the 2020 practice parameter update by the Journal of Allergy and Clinical Immunology 1. While relative contraindications might include concerns about cardiovascular effects in elderly patients or those with known heart disease, the benefits of epinephrine administration in anaphylaxis outweigh these concerns.

Some patient subgroups may be at higher risk for adverse effects during epinephrine therapy, including:

• Those with cardiovascular disease, who should be made aware that myocardial ischemia and dysrhythmias can occur in untreated anaphylaxis 1
• Patients receiving monoamine oxidase inhibitors, tricyclic antidepressants, stimulant medications, or abusing cocaine 1
• Individuals with certain pre-existing conditions, such as recent intracranial surgery, aortic aneurysm, uncontrolled hyperthyroidism, or hypertension 1

The standard dose for adults is 0.3-0.5 mg of 1:1000 (1 mg/mL) concentration administered intramuscularly in the mid-outer thigh, which can be repeated every 5-15 minutes if symptoms persist. For children, the dose is 0.01 mg/kg up to 0.3 mg. Patients should be monitored for potential side effects, including tachycardia, tremors, anxiety, and hypertension, but these are generally transient and manageable. Delayed administration of epinephrine is associated with increased mortality in anaphylaxis, so clinicians should not hesitate to administer this life-saving medication when indicated, as emphasized in the 2020 practice parameter update 1.

From the FDA Drug Label

8 USE IN SPECIFIC POPULATIONS

1. 1 Pregnancy Teratogenic Effects: Pregnancy Category C. 8.2 Labor and Delivery Use with caution during labor and delivery.
2. 3 Nursing Mothers It is not known whether epinephrine is excreted in human milk.
3. 4 Pediatric Use Clinical use data support weight-based dosing for treatment of anaphylaxis in pediatric patients,
4. 5 Geriatric Use Clinical studies for the treatment of anaphylaxis have not been performed in subjects aged 65 and over to determine whether they respond differently from younger subjects.

The FDA drug label does not explicitly state contraindications for administering epinephrine in cases of anaphylaxis, but it does provide precautions and warnings for specific populations, such as:

• Pregnancy: use only if the potential benefit justifies the potential risk to the fetus 2
• Labor and Delivery: use with caution due to potential uterine vasoconstriction and fetal anoxia 2
• Nursing Mothers: caution should be exercised as it is not known whether epinephrine is excreted in human milk 2
• Pediatric Use: weight-based dosing is supported, but adverse reactions are similar to those in adults 2
• Geriatric Use: consider starting with a lower dose due to potential concomitant disease or other drug therapy 2 However, the label does mention that epinephrine should be used with caution in patients with:
• Heart disease
• Hypertension
• Hyperthyroidism as these conditions may increase the risk of adverse reactions 2

From the Research

Contraindications for Administering Epinephrine in Anaphylaxis

There are no explicit contraindications for administering epinephrine in cases of anaphylaxis mentioned in the provided studies 3, 4, 5, 6, 7.

Special Considerations

• The studies emphasize the importance of prompt administration of epinephrine in anaphylaxis to prevent fatalities and minimize morbidity 3, 4, 5, 6, 7.
• They also highlight the need for education on the proper use of epinephrine auto-injectors and the importance of carrying them at all times for patients with known anaphylactic reactivity 4, 5.
• The route of administration is crucial, with intramuscular injection in the lateral thigh being the recommended method for adults and children 3, 4, 5.
• While there are no direct contraindications, the studies suggest that delays in epinephrine administration can be fatal, and other medications like antihistamines and corticosteroids may not be sufficient as first-line treatments for anaphylaxis 6, 7.

Key Points

• Epinephrine is the first-line treatment for anaphylaxis 3, 4, 5, 6, 7.
• Prompt administration of epinephrine is critical to prevent fatalities and minimize morbidity 3, 4, 5, 6, 7.
• Education on the proper use of epinephrine auto-injectors is essential for patients with known anaphylactic reactivity 4, 5.
• Other medications like antihistamines and corticosteroids may have a role in anaphylaxis management but are not recommended as first-line treatments 6, 7.