From the Guidelines
For anaphylaxis, immediately administer epinephrine (adrenaline) as the first-line treatment, using an epinephrine auto-injector such as EpiPen or Auvi-Q at a dose of 0.3mg for adults or 0.15mg for children weighing less than 30kg, injected into the mid-outer thigh, as recommended by the most recent guidelines 1. This approach is supported by the latest evidence, which emphasizes the critical role of epinephrine in managing anaphylaxis due to its rapid onset of action and its ability to address the pathophysiologic changes associated with anaphylaxis, including increased vasoconstriction, bronchodilation, and decreased release of mediators of inflammation 1. The administration of epinephrine should not be delayed, as prompt treatment is associated with better outcomes and reduced risk of morbidity and mortality 1. If symptoms persist after 5-15 minutes, a second dose of epinephrine may be administered, and patients should be monitored closely for signs of biphasic reactions, which can occur in up to 20% of cases 1. After giving epinephrine, calling emergency services, placing the patient in a supine position with legs elevated (unless they are having breathing difficulties), and removing the trigger if possible are also crucial steps in managing anaphylaxis. Secondary treatments, including H1-antihistamines like diphenhydramine, H2-blockers like ranitidine, bronchodilators for persistent wheezing, and IV fluids for hypotension, may be considered but should not delay the administration of epinephrine, as emphasized in the guidelines 1. Monitoring patients for at least 4-6 hours after symptoms resolve is essential due to the risk of biphasic reactions, highlighting the importance of close observation and readiness to provide additional treatment as needed 1.
From the FDA Drug Label
1 INDICATIONS & USAGE Adrenalin® is available as a single-use 1 mL vial and a multiple-use 30 mL vial for intramuscular and subcutaneous use. Emergency treatment of allergic reactions (Type I), including anaphylaxis, which may result from allergic reactions to insect stings, biting insects, foods, drugs, sera, diagnostic testing substances and other allergens, as well as idiopathic anaphylaxis or exercise-induced anaphylaxis.
For anaphylactic reactions, epinephrine (IM) should be given. The key points are:
- Emergency treatment for allergic reactions, including anaphylaxis
- Intramuscular administration
- Treatment of anaphylaxis with signs and symptoms such as flushing, apprehension, syncope, tachycardia, and others 2
From the Research
Treatment for Anaphylaxis
- The primary treatment for anaphylaxis is the administration of epinephrine (adrenaline) via intramuscular injection, typically in the lateral portion of the thigh 3, 4, 5, 6, 7.
- The recommended dose is 300-600 µg for adults and 10 µg/kg for children, which can be repeated every 10-15 minutes if necessary 3, 7.
- Epinephrine auto-injectors are commonly used for this purpose and should be prescribed to patients with a history of anaphylaxis to carry with them at all times 4, 7.
- It is essential to educate patients on the proper use of epinephrine auto-injectors to ensure timely and effective treatment in emergency situations 3, 4, 7.
Administration and Safety
- Intramuscular administration of epinephrine is preferred over intravenous administration due to a lower risk of serious cardiac adverse effects 3, 6.
- While there are potential risks associated with epinephrine administration, such as cardiovascular adverse events, the benefits of treatment far outweigh the potential harm, especially in life-threatening situations 6.
- Antihistamines and corticosteroids may be used as secondary treatments, but they should not delay the administration of epinephrine 5.
- Aggressive fluid resuscitation may also be necessary to treat intravascular volume depletion characteristic of anaphylaxis 5.