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How EpiPen® works

EpiPen® contains epinephrine, a medication that can help decrease your body’s allergic reaction by:
  • Relaxing the muscles in your airways to make breathing easier
  • Helping to reverse the rapid and dangerous decrease in blood pressure
  • Relaxing the muscles in the stomach, intestines and bladder

Side effects

Like all medicines, epinephrine may cause side effects.

Some side effects from using epinephrine may include paleness, dizziness, weakness, shaking, headache, throbbing, restlessness, anxiety, tenseness, or fear.

Serious side effects include difficulty breathing, increased heart rate (pounding heart), irregular or skipped heart beats, chest pain (also called angina), and stroke. The symptoms of stroke are blurred vision, difficulty speaking, headache, dizziness, and weakness.

If you experience any of the serious side effects, stop taking epinephrine and get immediate medical help.

This is not a complete list of side effects. For any unexpected effects while taking EpiPen® or EpiPen Jr®, talk to your doctor or pharmacist.

It is important that you seek medical assistance or go to the emergency room immediately after using EpiPen® or EpiPen Jr®.

Medical treatment

Even after epinephrine has been administered, you must seek immediate medical attention or go to the emergency room.

A second reaction can occur up to 38 hours after your initial reaction.

You will need professional care to determine whether additional epinephrine, steroids, antihistamines or other treatments are required.

Once you are discharged from the hospital, you should have an EpiPen® Auto-Injector available. You should also stay close to a healthcare facility or be able to call 911 for the next 48 hours.

Consider having more than one EpiPen® on hand in your home and when going out.