Epinephrine Dosing for Chemotherapy-Induced Anaphylaxis
For chemotherapy-induced anaphylaxis, administer epinephrine 0.3-0.5 mg (0.3-0.5 mL of 1:1000 concentration) intramuscularly in the anterolateral thigh for adults and children ≥30 kg, or 0.01 mg/kg (maximum 0.3 mg) for children <30 kg. 1
Dosing Guidelines
Adults and Children ≥30 kg (66 lbs):
- 0.3-0.5 mg (0.3-0.5 mL) of 1:1000 concentration epinephrine
- Administer intramuscularly in the anterolateral thigh
- Maximum 0.5 mg per injection
- May repeat every 5-10 minutes as necessary based on clinical response 1
Children <30 kg (66 lbs):
- 0.01 mg/kg (0.01 mL/kg) of 1:1000 concentration epinephrine
- Administer intramuscularly in the anterolateral thigh
- Maximum 0.3 mg per injection
- May repeat every 5-10 minutes as necessary based on clinical response 1
Administration Technique
- Inject through clothing if necessary
- For children, hold the leg firmly in place to minimize risk of injection-related injury 1
- Use a needle long enough (at least 1/2 inch to 5/8 inch) to ensure intramuscular delivery 1
- Do not administer repeated injections at the same site to avoid tissue necrosis from vasoconstriction 1
Important Clinical Considerations
- Intramuscular injection in the lateral thigh (vastus lateralis) is the preferred route for first-aid treatment of anaphylaxis 2
- Studies have shown that intramuscular injection in the lateral thigh leads to faster peak plasma epinephrine concentrations (8 ± 2 minutes) compared to subcutaneous injection (34 ± 14 minutes) 2
- Monitor the patient clinically for severity of the allergic reaction and potential cardiac effects 1
- Prepare for a second dose if symptoms persist or worsen after 5-15 minutes 3
- Between 6-19% of patients require a second dose of epinephrine 3
Auto-Injector Selection
When using auto-injectors for chemotherapy-induced anaphylaxis:
- For adults and children ≥30 kg: Use 0.3 mg epinephrine auto-injector
- For children 15-30 kg: Use 0.15 mg epinephrine auto-injector
- For infants and small children 7.5-15 kg: Use 0.1 mg epinephrine auto-injector (if available) 3, 4
Cautions and Monitoring
- Inspect solution visually before administration; do not use if colored, cloudy, or contains particulate matter 1
- Monitor vital signs, including blood pressure, heart rate, and oxygen saturation 3
- Position patients with hypotension in a supine position with legs elevated 3
- Administer fluid resuscitation (1-2 liters of normal saline at 5-10 mL/kg) for hypotensive patients 3
- Provide supplemental oxygen for patients with respiratory symptoms or those receiving multiple doses of epinephrine 3
Follow-up Care
- Observe patients for at least 4-6 hours after chemotherapy-induced anaphylaxis due to risk of biphasic reactions 3
- High-risk patients may require extended observation up to 6 hours or longer, including hospital admission 3
- Consider referral to an allergist/immunologist for identification of triggers and long-term management 3
Remember that while antihistamines and glucocorticoids may be used as adjunctive therapy, they should never delay or replace epinephrine administration, which remains the cornerstone of anaphylaxis management 3, 5.