Anaphylaxis 101 (& Epinephrine)
Anaphylaxis is an allergic reaction that has life-endangering effects on the circulatory and respiratory systems. Anaphylaxis is an almost immediate, rapidly progressive multi-system allergic reaction to a foreign protein injected into the body by stinging and biting insects, snakes, and sea creatures or ingestion or inhalation of food, chemicals, and medications.
Early recognition and prompt treatment of anaphylaxis, particularly in a wilderness setting, is essential to preserve life. The onset of symptoms usually follows quickly after an exposure (minutes after a sting or bite, within 30-60 minutes following ingestion). Over 20% of all anaphylactic reactions are biphasic reactions, meaning the swelling of the airway can reoccur within one to 72 hours after the original attack.
In addition to shortness of breath, weakness and dizziness, persons suffering from anaphylaxis also frequently complain of a sense of impending doom, cough, chest tightness, trouble swallowing, abdominal cramps, or generalized itching.
Physical findings include rapid heart rate, low blood pressure, and other evidence of shock, upper airway obstruction (stridor) and lower airway obstructions (wheezes) with labored breathing, generalized skin redness, hives, and swelling of the mouth, face, and neck.
Epinephrine should only administered to patients having symptoms suggestive of an acute systemic reaction (i.e. generalized skin rash, difficulty breathing, fainting, or facial swelling).
Maintain an open airway, assist ventilations if necessary, and put patient in a position of comfort. Initiate CPR if necessary.
Inject 0.3 mg of 1/1000 epinephrine into the lateral thigh of an adult over 66 pounds (0.15 mg for a child, 33-66 pounds).*
Repeat injections every 5 minutes if condition worsens or every 15 minutes if condition does not improve, for a total of up to three doses.
Administer 50–100 mg of diphenhydramine by mouth every 4–6 hours if the patient is awake and can swallow.
Consider Prednisone 40–60 mg / day (or equivalent dose of an oral corticosteroid).
Because a rebound reaction can occur, all victims of an anaphylactic reaction should be evacuated. Rebound (biphasic) reactions should be treated in the same manner as the initial reaction, using epinephrine in the same dosage.
* There is 1 mg of epinephrine in 1 ml of epinephrine 1/1000; there are 0.3 mg in 0.3 ml of 1/1000. Pre-loaded commercially available injectors deliver either 0.3 mg (standard adult dose) or 0.15 mg (standard pediatric dose). If the person weighs less than 66 lbs (30 kg), the doses are: epinephrine is 0.01 mg/kg; diphenhydramine is 1mg/kg; and prednisone is 1 - 2mg/kg. When using lbs, multiply the weight times 0.45 to get the weight/mass in kilograms.
IN THE NEWS
Via the Associated Press (June 15, 2017)
U.S. regulators have approved new competition for EpiPen, the emergency allergy medicine that made Mylan a poster child for pharmaceutical company greed. The Food and Drug Administration on Thursday approved Adamis Pharmaceuticals Corp.’s product, which should go on sale later this year.
Symjepi is a syringe pre-filled with the hormone epinephrine, which helps stop life-threatening allergic reactions from insect stings and bites, foods such as nuts and eggs, or certain medications. San Diego-based Adamis says its product is easier to use than Mylan’s EpiPen, a spring-loaded syringe filled with a set dose that comes with a training device. Symjepi also is smaller than EpiPen, so it’s easier to fit in a pocket or purse. Most children and adults with severe food or insect allergies carry a device wherever they go and leave a spare at home, school or work.
Adamis said it is still lining up a distributor so it hasn’t set the exact price for its product, which will be sold in pairs like EpiPen. Adamis says that Symjepi is intended to be a “low-cost alternative” to EpiPen and similar products, and the company is aiming to sell it for far less than generic EpiPens. Currently, EpiPens cost about $630 to $700 without insurance while the new generic version retails for still about $225 to $425.
Mylan, which has U.S. headquarters near Pittsburgh, launched generic EpiPens last December in an effort to deflect mounting criticism. Last summer, the company came under fire for repeatedly raising the price of EpiPens and CEO Heather Bresch was grilled by a Congressional panel. Mylan hiked the price of a pair of EpiPens from $94 in 2007, when the company acquired the product, to $608 last year. The devices need to be replaced each year, adding to the financial sting.
Analysts and others have estimated that it costs less than $20 to produce a pair of EpiPens. While EpiPen has other rival products, doctors tend to prescribe EpiPen because it’s so well known. According to QuintilesIMS, a pharmaceutical analytics company, just three years ago, EpiPens accounted for nearly 90 percent of both revenue and prescriptions filled in the U.S. for epinephrine injectors and syringes. In the first quarter of this year, brand-name EpiPens only drew about 60 percent of epinephrine device prescriptions, while generic EpiPens — mostly Mylan’s — had captured 38 percent of prescriptions.
The company is preparing to apply for FDA approval of a “junior version” of Symjepi. That would contain a lower epinephrine dose than Symjepi, and would compete with Mylan’s EpiPen Jr.