How should epinephrine be used?
Epinephrine administered into the side of the thigh is the preferred route. 0.3mg (Epipen strength) – 0.5mg is recommended for adults. This can be repeated every 5-15 minutes as necessary. 16-35% of patients need a second dose of epinephrine to manage initial symptoms. Epipen Jr. contains 0.15mg epinephrine, which is usually recommended up to 66 lbs. Dosage for children is 0.01 mg/kg.
Aqueous epinephrine diluted 1:1000, 0.1-0.3ml in 10ml NS can be used intravenously over several minutes as needed. For potentially dying subjects, epinephrine diluted 1:1000, 0.1ml in 0.9ml of blood or normal saline (1:10000) intravenously. Give as necessary for response.
Aqueous epinephrine diluted 1:1000, 0.1-0.2mg, can be administered at reaction site (bee sting, etc.)
Statements on the use of epinephrine
Intramuscular adrenaline is the acknowledged first line therapy for anaphylaxis, in hospital and in the community, and should be given as soon as the condition is recognized. There are no absolute contraindications to administering adrenaline in children. Absolute indications for prescribing self-injectable adrenaline and prior cardiorespiratory reactions, exercise-induced anaphylaxis, idiopathic anaphylaxis and persistent asthma with food allergy. Relative indications include peanut or tree nut allergy, reactions to small quantities of a given food, food allergy in teenagers, and living far away from a medical facility.
Reference: Muraru A et al. Allergy 2007; 62:857-71.
Statement of the World Allergy Organization
The Committee strongly believes that epinephrine is current under-utilized and often dosed suboptimally to treat anaphylaxis, is under-prescribed for potential future self-administration, that most of the reasons proposed to withhold its clinical use are flawed, and that the therapeutic benefits of epinephrine exceed the risk when given in appropriate IM doses.
Reference: Kemp SF, Lockey RF, Simons FER, et al. Allergy 2008; 63:1061-1070.
Epinephrine may cause pharmacologic adverse effects such as anxiety, fear, restlessness, headache, dizziness, palpitations, pallor, tremor. Rarely, especially after overdose, it may lead to ventricular arrhythmias, angina, MI, pulmonary edema, sudden sharp increase in BP, intracranial hemorrhage. There is, however, no absolute contraindication to epinephrine use in anaphylaxis.
Reference: Simons FER. J Allergy Clinical Immunol 2004;113:837-44.