How effective is an epi-pen?

Question

I know it isn't enough in all cases. Can anyone give me a statistic? Or explain why it doesn't always work? Thanks.

Answer 1

EpiPens manufactured before December 2004 carried instructions for use stating that after the locking cap was removed, the device was put to the injection site and then pressure was applied to activate the mechanism.

All EpiPens manufactured since December 2004 carry a new version of the instructions, which are assumed to be more intuitive.[3] In the new instructions, approved by the Government’s Medicines and Healthcare products Regulatory Agency (UK), a patient uses the device by removing the gray locking cap from the top of the device, forming a fist around the unit, and jabbing it firmly into a thigh until the click of the spring-loaded needle activating is heard. Both sets of instructions are valid.

Regardless of the instruction version, after activation the patient holds the device in place for 10 seconds as the epinephrine is delivered. This gives the drug enough time to be absorbed by the body's muscles and diffused into the bloodstream. Using the device intravenously is highly discouraged, and can even be lethal as epinephrine is a local vascular constrictor, and use intravenously can restrict blood flow to the area of the injection site, causing subsequent damage to extremities. Additionally, intravenous administration of the EpiPen can cause ventricular tachycardia, or dangerously rapid heartbeat. [4] After administering the device, patients are advised to seek immediate medical attention. Directions for use of the injector are found on the device itself.

EpiPen is manufactured by DEY L.P. EpiPens are commonly carried by persons with severe allergies and a risk of anaphylactic shock because they can be self-administered and are very fast-acting. In the UK and US, EpiPens are regulated medical devices and require a prescription. In Canada, EpiPens may be purchased without a prescription, but they are kept behind pharmacy counters.

The standard dosage of epinephrine supplied by an EpiPen is 0.3 ml of 1 in 1000 Parts (0.3 mg). Child-sized dosages (0.15 mg) are available as the EpiPen JR. In the US, EpiPen JR is recommended for children 33-66 lb.[1], while in Canada it is recommended for children 15 to 30kg. [2]

The EpiPen contains a spring-loaded needle that shoots through a membrane in the tip and into the recipient's body to deliver the medication.

EpiPen usually has a shelf life of 20 months, when the EpiPen should be discarded if unused, by returning it to a local pharmacy or hospital for safe disposal. Using an EpiPen that has expired is discouraged but better than nothing in an emergency.

The original carrying tube that the pen came in was easily broken; however, the manufacturer has recently begun shipping EpiPens in more durable carrying tubes with significantly thicker plastic walls, a s***w top, and metal plating at the bottom (needle) end to prevent puncture injuries.

Despite being trademarked, common usage of the word "epipen" is drifting toward the generic context of any epinephrine autoinjector.[

Hope I helped. :)

Answer 2

It works every time, but what it does is limited and should be taken in context.

The treatment of type I allergic reactions is primarily antihistamines and steroids (glucocorticoids). The vasoconstriction of epinephrine is useful as a supporting measure, and the dosage requirements obviously depend on the size of the victim and the severity of the allergic reaction. In fact, the dose in an Epi-pen is lower than the standard dose commonly used in the monitored conditions of an emergency department.