Epinephrine is a chemical that narrows blood vessels and opens airways in the lungs. These effects can reverse severe low blood pressure, wheezing, severe skin itching, hives, and other symptoms of an allergic reaction.

Epinephrine injection is used to treat severe allergic reactions (anaphylaxis) to insect stings or bites, foods, drugs, and other allergens. Epinephrine is also used to treat exercise-induced anaphylaxis.

Epinephrine auto-injectors such as EpiPen and EpiPen Jr. may be kept on hand for self-injection by a person with a history of an severe allergic reaction.

Epinephrine injection may also be used for purposes not listed in this medication guide.

Before using this medication, tell your doctor if you have heart disease or high blood pressure, a heart rhythm disorder, coronary artery disease, Parkinson's disease, diabetes, or a thyroid disorder.

Before using epinephrine, tell your doctor about all other medications you use, especially digoxin (digitalis, Lanoxin), heart or blood pressure medicine, heart rhythm medication, an antidepressant, a diuretic (water pill), thyroid medication, migraine headache medicine, cold or sleep medicine that contains an antihistamine, or an MAO inhibitor such as Marplan, Nardil, Azilect, Eldepryl, Emsam, or Parnate.

Seek emergency medical attention even after you use epinephrine to treat a severe allergic reaction. The effects of epinephrine may wear off after 10 or 20 minutes. You will need to receive further treatment and observation.

Before using epinephrine a second time, tell your doctor if your first injection caused a serious side effect such as increased breathing difficulty, or dangerously high blood pressure (severe headache, blurred vision, buzzing in your ears, anxiety, confusion, chest pain, shortness of breath, uneven heartbeats, seizure).

To make sure you can safely use epinephrine, tell your doctor if you have any of these other conditions:

• heart disease or high blood pressure;

• a heart rhythm disorder;

• coronary artery disease;

• Parkinson's disease;

• diabetes; or

• a thyroid disorder.

FDA pregnancy category C. It is not known whether epinephrine will harm an unborn baby. If possible before using this medicine, tell your doctor if you are pregnant.

Do not use epinephrine without your doctor's advice if you are breast-feeding a baby.

In an emergency situation, it may not be possible before you use epinephrine to tell your caregivers if you are pregnant or breast-feeding. Make sure any doctor caring for your pregnancy or your baby knows you have received this medication.