The most effective treatment for acute life threatening anaphylaxis is an intra-muscular injection of adrenalin (epinephrine). Research shows that the available auto- injectors are expensive, often under-utilised and more than often, the wrong dose is given. Three products compete are on the UK fixed-dose adrenalin injector market: Epipen, Anapen and Jext.
The market leader being – Epipen 300mcg (for adults) and Epipen 150mcg (for children over 30kg). However, research shows that the adult Epipen may be too weak for an average adult (over 60kg) and the children’s standard auto-injector dose is too strong to give to a child under 15kg (or less than 3 years old).
But there are three versions of Anapen, one contains 500mcg adrenalin for adults over 60kg, a 300mcg for children and adults over 30kg (over 8 years old) and also a 150mg for children weighing 15kg to 30kg (under 6 years old)
The third product that I recently discovered is called Jext, with two formulations: 300mcg for adults and 150mcg for children. The Jext auto-injector has a 24 month shelf-life as opposed to 12 months for Epipen’s and Anapen’s.
So why are most anaphylaxis sufferers prescribed an Epipen (or two)? That’s because old habits die hard!
Reference: Nowak R, Farrar JR, Brenner BE et al, Customizing anaphylaxis guidelines for emergency medicine. J Emergency Med 2013 (13) 102-109.
