Adrenaline (Epinephrine) & It's use in Anaphylaxis
Vincent St Aubyn Crump
Adrenaline is a hormone naturally secreted by the medulla (inner portion) of the
adrenal gland, which are situated just above the kidneys. This hormone is secreted
along with noradrenaline (norepinephrine) to bring about the "flight or fight" response
in times of stress, exercise, and response to low blood sugar. It prepares the body
for strenuous activity or life-threatening situations. Increased secretion caused
by fear or anger results in increased heart rate, and glycogen in the liver is broken
down to glucose. The hormone was first extracted from the adrenal gland of animals
in 1901, and first synthesized in 1904.
In medicine adrenaline is used to treat:
- Cardiac arrest - stimulates the heart
- Asthma - acts as a bronchodilator (opens up the airways)
- Glaucoma - when applied topically to the eyes it decreases intra-ocular pressure
- Dental analgesia - added to local anaesthetic to reduce bleeding
Actions of Adrenaline
- Increased metabolism
- Cardiac stimulant & Increased heart rate
- Increased blood pressure
- Increased mental activity
- Increased blood flow to muscles
- Constriction of blood vessels (vasoconstriction)
Side Effects of Adrenaline
- Anxiety (transient), Fear & Tremor
- Cold fingers and toes and dry mouth (due to vasoconstriction)
- Pallor ("white as a sheet") - also due to vasoconstriction
- Cardiac arrhythmias, Angina, and excessive rise in blood pressure
- Intracerebral bleeding leading to strokes
Adrenaline may be administered in life-threatening anaphylactic reactions, even
when the followingrelative contraindications are present:
- Coronary artery disease
- Uncontrolled hypertension
- Serious ventricular arrhythmias (life-threatening abnormal heart rhythm)
- Second stage of labour
- Sympathomimetics like ventolin & isoprenaline cause additive effects
- Beta-blockers antagonize therapeutic effects of adrenaline
- Digitalis potentiates the proarrhythmic effects of adrenaline
- Phenothiazine causes a paradoxical decrease in blood pressure
- Monoamine oxidase inhibitors (MOAIs) potentiate the cardiovascular effects of adrenaline
Use of Adrenaline in Pregnancy
Classified as Pregnancy Category A: Adrenaline has been given to a large number
of pregnant women and women of child-bearing age without any proven increase in
the frequency of malformations or other direct or indirect harmful effects on the
foetus having been observed.
Use with caution in elderly and patients that have:
- Cardiovascular disease (angina, arrhythmias)
- Prostatic enlargement
Rapid intravenous infusion can cause death from cerebrovascular hemorrhage or cardiac
Dosage & Administration in Anaphylaxis
Adrenaline 1:1000, 0.3 to 0.5 mL (0.3-0.5mg), administered slowly. The dose may
be repeated every 10 minutes if necessary. In severe reactions the dose can be increased
to 1mL. The intramuscular route is better than the subcutaneous route. Adrenaline
1:1000 should never be injected intravenously.
Children up to 12 years of age
Adrenaline 1:1000, 0.01ml / Kg (minimum 0.1ml 1:1000).
How is adrenaline supplied (in New Zealand)
Injection: : 1/1000, 1ml (Baxter)
Adrenaline Injection is available in a single use ampoule containing 1mg adrenaline
acid tartrate in 1mL (1:1,000). It is supplied in packs of 5 or 50.
Injection: 1/10000 (Baxter)
Adrenaline Injection 1/10,000 is available in single use ampoules containing 1mg
adrenaline acid tartrate in 10 mL (1:10,000). It is presented in packs of 5 or 50.
This preparation is more suitable for intravenous use, preferably with cardiac monitoring.
A study done by Dr Estelle Simons in Winnipeg, Canada showed that adrenaline for
out-of-hospital (first-aid) treatment of anaphylaxis in infants, the ampoules/syringe/needle
method is not practical. Most parents were unable to draw up an infant adrenaline
dose rapidly or accurately. (J Allergy Clin Immunol 2001; 108:1040-4)
Injection: 1/1000 Min-I-jet (CSL) )
Adrenaline Injection is available in a single use prefilled MIN-I-JET syringe containing
1 mg adrenaline hydrochloride in 1 mL (1:1,000).
- Epipen® & Epipen® junior (only form available in NZ).
The EpiPen® auto-injector is disposable drug delivery system featuring spring activation
and a concealed needle. It is designed for self-administration of adrenaline in
acute allergic emergencies (anaphylaxis)
The Epipen® and Epipen® Jr auto-injectors contain 2mls of adrenaline for emergency
intramuscular use. Each EpiPen auto-injector delivers a single dose of 0.3mg adrenaline
from adrenaline injection UPS, 1:1000 (0.3ml) in a sterile solution.
The EpiPen® Jr auto-injector delivers 0.15mg adrenaline injection UPS, 1:2000 (0.30ml)
in a sterile solution. EpiPen contains sodium metabisulfite as preservative, but
contains no latex.
They should be stored in a dark place at room temperature. Should not be refrigerated.
EpiPen and EpiPen Jr should only be injected in the outer thigh (antero-lateral
portion). (Never in the buttocks)
When should adrenaline be given in (suspected) Anaphylaxis?
The ASCIA Anaphylaxis Action Plan (NZ version)
Mild to Moderate Allergic Reaction
- Swelling of lips, face, eyes
- Hives or welts
- Abdominal pain, vomiting
IF IN DOUBT GIVE EPIPEN® OR EPIPEN® Jr
- Stay with child and call for help
- Give medications if prescribed (eg. Antihistamines)
- Locate EpiPen® or EpiPen® Jr
- Contact parent / carer
WATCH FOR SIGNS OF ANAPHYLAXIS (severe allergic reaction)
- Difficulty / noisy breathing
- Swelling of tongue
- Swelling / tightness in throat
- Difficulty talking and / or hoarse voice
- Wheeze or persistent cough
- Loss of consciousness and / or collapse
- Pale and floppy (young children)
- Give EpiPen® or EpiPen® Jr
- Call Ambulance. Telephone 111
- Contact parent / carer
Adrenaline dosing is based on body weight. Normal adult dose of adrenaline in anaphylaxis
is 0.30mg (0.30ml of 1:1000 adrenaline).
The Pediatric dose is 0.01ml / Kg (minimum 0.1ml 1:1000). The EpiPen® Jr has 0.15mg
adrenaline, which is the dose for a child weighing 15Kg. This might be too much
for a 5Kg child, but not enough for a 25Kg child. For children weighing 15Kg to
30 Kg it is advisable to give EpiPen® instead of EpiPen® Jr, but one should bear
in mind that this dose will have more side effects (tremor, palpitations, headaches
Can Adrenaline Inhalations be substituted for adrenaline injection in children at
risk for systemic anaphylaxis?
This question was answered by a study done by Dr Estelle Simons, et al, Winnipeg,
Canada. (Pediatrics Vol. 106 No. 5 November 2000, pp 1040 -1044)
The study concluded: " Despite expert coaching, because of the number of adrenaline
inhalation required and the bad taste of the inhalations, most children were unable
to inhale sufficient adrenaline to increase their plasma adrenaline concentrations
promptly and significantly...