These devices help inform providers of the allergy in emergency situations. The drugs used can all have side effects. Antihistamines can cause sleepiness. Prednisone can cause stomach problems, sleep problems, and mood swings. These side effects are generally very mild.
Asthma medications can cause shakiness and abnormal heart rate.
These, too, tend to be mild. Epinephrine can cause significant anxiety, shakiness, as well as abnormal heart rate. This drug is often administered in the doctor's office or emergency room. The person should avoid the drug that caused the allergic reaction. A person should wear jewelry or a carry a card to identify the allergy in case of an emergency.