EpiPen Dosing for a 13-Year-Old Male Weighing 140 Pounds
For a 13-year-old male who is 5'10" and weighs 140 pounds (>30 kg), the appropriate dose is 0.3 mg of epinephrine using the standard EpiPen (not EpiPen Jr). 1, 2
Dosing Rationale
The FDA-approved dosing guidelines for epinephrine in anaphylaxis are clear:
- Adults and children ≥30 kg (66 lbs): 0.3 to 0.5 mg intramuscularly 1
- Children <30 kg (66 lbs): 0.01 mg/kg, up to 0.3 mg maximum 1
Since this 13-year-old weighs 140 pounds (approximately 63.5 kg), which is well above the 30 kg threshold, the appropriate dose is 0.3 mg using the standard EpiPen, not the EpiPen Jr (0.15 mg) which is intended for smaller children.
Administration Technique
- Inject intramuscularly into the anterolateral aspect of the thigh (mid-outer thigh) 2, 1
- The injection can be administered through clothing if necessary 1
- Hold the auto-injector in place for 3 seconds after triggering 2
- A second dose may be administered after 5-15 minutes if symptoms persist or worsen 3, 4
Important Clinical Considerations
- Epinephrine is the first-line treatment for anaphylaxis and should be administered immediately upon recognition of symptoms 2, 5
- There are no absolute contraindications to epinephrine administration in anaphylaxis 3, 6
- The patient should be placed in a recumbent position with legs elevated if hypotensive 2
- After administration, the patient should be transported to an emergency department for further monitoring 2
- Approximately 8-28% of anaphylaxis cases require a second dose of epinephrine 4
Potential Adverse Effects
- Common side effects include anxiety, tremor, pallor, palpitations, dizziness, and headache 1
- More serious but rare adverse effects include ventricular arrhythmias and increased blood pressure 1
- The benefits of epinephrine in anaphylaxis far outweigh the risks when given at appropriate doses 6
Follow-up Care
- The patient should be observed for at least 4-6 hours after symptom resolution 2
- Prescribe two epinephrine auto-injectors for future use 2
- Refer to an allergist for identification of triggers and long-term management 2
Remember that prompt administration of epinephrine is critical in anaphylaxis management, and delays can result in poor outcomes or death, particularly in adolescents with asthma 2.