EPIPEN

What it is

EPIPEN is available in two strengths: Jext Jnr 150, which delivers a single dose of 150 micrograms of adrenaline (epinephrine) as acid tartrate, and Jext 300, which delivers a single dose of 300 micrograms of adrenaline (epinephrine) as acid tartrate. The medicine is supplied as a solution for injection in a pre-filled cartridge based auto-injector.

Approved indications

— Emergency treatment of anaphylaxis (acute severe allergic reactions) due to insect stings, or bites, foods, drugs or other allergens.

Dosing overview

For patients between 15 kg and 30 kg in weight, the usual dose is 150 micrograms. Children and adolescents weighing over 30 kg should be prescribed the 300 microgram strength, as should adults. Larger adults may require more than one injection to reverse the effect of an allergic reaction. In the absence of clinical improvement or if deterioration occurs, a second injection with an additional dose may be administered 5–15 minutes after the first injection. It is recommended that patients are prescribed two auto-injector pens which they should carry at all times.

Key safety warnings

Patients should be advised not to inject EPIPEN into the gluteus maximus due to the risk of accidental injection into a vein, and intravenous administration must be avoided as cerebral haemorrhage may occur due to a sharp rise in blood pressure. EPIPEN contains sodium metabisulfite which may rarely cause severe hypersensitivity reactions including anaphylactic symptoms and bronchospasm in susceptible people, especially those with a history of asthma. Due to an increased risk of adverse reactions following administration of adrenaline (epinephrine), special caution should be taken in patients with cardiovascular diseases including angina pectoris, obstructive cardiomyopathy, cardiac arrhythmia, cor pulmonale, atherosclerosis and hypertension. Adrenaline can cause potentially fatal ventricular arrhythmias including fibrillation, especially in patients with organic heart disease or those receiving other drugs that sensitise the heart to arrhythmias. Rare cases of serious skin and soft tissue infections, including necrotising fasciitis and myonecrosis caused by Clostridia (gas gangrene), have been reported at the injection site following adrenaline injection for anaphylaxis. To decrease the risk of Clostridium infection, do not inject EPIPEN into the buttock. Patients and carers should be informed about the possibility of biphasic anaphylaxis which is characterised by initial resolution followed by recurrence of symptoms some hours later.

Contraindications

There are no absolute contraindications to the use of EPIPEN during an allergic emergency.

PBS listing

Both the 300 microgram and 150 microgram strengths are listed on the PBS as intramuscular injection auto-injectors with authority required restriction, each at an ex-manufacturer price of A$67.19.

Regulatory history

EPIPEN received initial ARTG registration on 20 August 1993, with two variants registered: the 0.3 mg/0.3 mL auto-injector and the 0.15 mg/0.3 mL junior auto-injector.