ANAPEN

What it is

ANAPEN is adrenaline (epinephrine) acid tartrate supplied as a pre-filled auto-injector pen available in two strengths: ANAPEN Junior 150 delivering 150 micrograms per 0.15 mL dose, and ANAPEN 300 delivering 300 micrograms per 0.30 mL dose. The medicine is supplied as a solution for injection in a pre-filled cartridge-based auto-injector. ANAPEN contains sulfites as an excipient with known effect.

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 weighing between 15 kg and 30 kg, the usual dose is 150 micrograms. Children and adolescents weighing over 30 kg should be prescribed ANAPEN 300. For adults aged 30 kg and over, the usual dose is 300 micrograms. Larger adults may require more than one injection to reverse the effect of an allergic reaction. An initial dose should be administered as soon as symptoms of anaphylaxis are recognised. If there is no clinical improvement or if deterioration occurs, a second injection with an additional ANAPEN may be administered 5–15 minutes after the first injection. It is recommended that patients are prescribed two ANAPEN pens which they should carry at all times. ANAPEN is for intramuscular administration into the anterolateral thigh.

Key safety warnings

Do not inject intravenously as cerebral haemorrhage may occur due to a sharp rise in blood pressure. Patients should be advised not to inject ANAPEN into the gluteus maximus due to the risk of accidental injection into a vein. 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, as Clostridium spores can be present on the skin and introduced into deep tissue with subcutaneous or intramuscular injection. To decrease the risk of Clostridium infection, do not inject ANAPEN into the buttock. ANAPEN 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. Special caution should be taken in patients with cardiovascular diseases including angina pectoris, obstructive cardiomyopathy, cardiac arrhythmia, cor pulmonale, atherosclerosis and hypertension, due to an increased risk of adverse reactions following administration of adrenaline. Patients 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 ANAPEN during an allergic emergency.

PBS listing

ANAPEN 500 micrograms in 0.3 mL single dose syringe auto-injector is listed on the PBS with authority required restriction at an ex-manufacturer price of A$67.19.

Regulatory history

ANAPEN Junior 150, ANAPEN 300 and ANAPEN 500 were first registered on the ARTG on 23 March 2021.