Epinephrine autoinjector
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EpiPen is a registered trademark for the most commonly used autoinjector of epinephrine (aka adrenaline), used in medicine to treat anaphylactic shock.
Description
EpiPen is manufactured by Meridian Medical Technologies, Inc. for 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 U.S. and the UK, 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. There are two valid sets of instructions for use as of the present. In the new set of 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. These instructions are assumed to be more intuitive than the old instructions, in which after the locking cap was removed, the device was put to the injection site and then pressure was applied to activate the mechanism. Both sets of instructions are valid, but all EpiPens manufactured since December 2004 carry the new instructions. [3] Regardless of the instruction version, after activation the patient holds the device in place for 10-15 seconds as the epinephrine is delivered. This gives the drug enough time to be absorbed by the body's subcutaneous tissue. 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 and/or limbs. Additionally, intravenous administration of the EpiPen can cause ventricular tachycardia, or dangerously rapid heartbeat, due to the tendency of epinephrine to accelerate the heartbeat of the patient. [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 usually has a shelf life of about 12 months, or until the contents contain a precipitate or discolor. Once this occurs, the EpiPen should be discarded if unused by returning it to a local drugstore, 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 screw 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.[citation needed]
Alternatives
Companies other than Dey have begun to market similar devices, such as the Twinject. Ampules of epinephrine are also available for single use in physician offices. Neither device prevents future episodes of anaphylaxis, but patients who experince severe or life threatening reactions may be treated with a series of allergy injections composed of increasing concentrations of naturally occuring substances such as venom to provide excellent and usually life-long protections against future insect stings. [1]
See also
References
- "EpiPen.com - Dosing." Accessed on December 5, 2006.
- "Calgary Allergy Network." Accessed on December 5, 2006.
- "The Anaphalaxis Campagin." Accessed on March 19, 2007.
- "BMJ Clinical Review of Epinephrine Administration." Accesed on March 19, 2007.
External links
- US EpiPen information
- Canadian EpiPen information
- Anaphalaxis Campaign
- A discussion forum for UK peanut anaphylaxis sufferers
- LIFELINE site with various patient information
- ^ Resiman, R (1994). "Insect Stings". New England Journal of Medicine. 26: 523–7.
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