Some people have serious allergies to things that don’t bother other people: A bee sting or a bite of shellfish, for example, can cause people allergic to them to have trouble breathing and even die. But a drug known as epinephrine, or adrenaline, which mimics natural fight-or-flight hormones in the body, may be used to open airways and treat sudden allergic reactions.

Delivered by injection, epinephrine jump-starts the heart and relaxes airway muscles. It can also help treat the anaphylactic shock, wheezing, shortness of breath, and swollen or closed lungs that result from allergic reactions. In addition, it tightens blood vessels, which raises dangerously low blood pressure. Epinephrine is also used to treat people who go into cardiac arrest.

People who suffer severe allergic reactions often carry prefilled, single-use, automatic epinephrine injection devices with them (brand names include EpiPen and Twinject) that can be stuck into the thigh if a reaction occurs. After injecting themselves, people should go to the hospital and avoid physical activity. Injections can cause side effects such as upset stomach, sweating, dizziness, weakness, paleness, headache, and uncontrollable shaking.

Epinephrine may also be prescribed as a liquid eyedrop formula to treat glaucoma or administered during eye surgery to reduce pressure in the vessels around the eyes. These eyedrops may cause temporarily blurred or decreased vision, stinging or irritated eyes, and headache. Symptoms of too much medicine being absorbed into the body include fast or irregular heartbeat, faintness, increased swelling, paleness, and trembling.

People with asthma, diabetes, eye disease, heart or blood vessel disease, high blood pressure, sulfite allergies, or an overactive thyroid may not be able to take epinephrine.

ADDITIONAL FACTS

  1. Both the Latin word ad and the Greek word epi mean “near” or “around.” The Latin ren and Greek nephros both mean “kidney.” Thus we have the adrenal gland, which sits on top of the kidney and secretes epinephrine.
  2. The term adrenaline junkie is often used to describe someone who seems to be addicted to thrilling or stressful behavior that releases natural adrenaline, such as extreme sports and risk taking.
  3. For as many as 35 percent of people, a single dose from an EpiPen is not enough to stop a severe allergic reaction, and they may require a second injection.