Treatment for drug allergies includes understanding what to do if you have a severe allergic reaction, avoiding the medicine that causes the allergy, and using medicines such as antihistamines for mild symptoms.

Emergency treatment

Call 911 or other emergency services immediately if:

• You develop hives and have trouble breathing or other symptoms of anaphylaxis. If you have an epinephrine shot, give it to yourself while you have someone else call 911. See pictures of hives and a skin rash caused by a drug allergy. For more information, see:

Allergies: Giving yourself an epinephrine shot.

Allergies in children: Giving an epinephrine shot to a child.

If you have a severe allergic reaction, your first treatment may occur in an emergency room, or emergency personnel may treat you where the reaction occurs. If you have not already given yourself an epinephrine shot, you may get one to help you breathe. You may also get antihistamines and corticosteroids.

Other treatment

You treat a drug allergy by avoiding the medicine that causes the allergic reaction. When your doctor knows which medicine is causing your reaction, he or she will find another medicine for you to use. If this is not possible, your doctor may suggest desensitization therapy.

In desensitization therapy, you start taking small amounts of the offending medicine and gradually increase how much you take. This lets your immune system "get used to" the medicine, and you may no longer have an allergic reaction to it. Because you may have a severe reaction during this therapy, it is done where emergency medical help is available and under the supervision of a health professional.

If you have a mild allergic reaction, several medicines may help ease symptoms. Prescription or over-the-counter antihistamine tablets or syrup, such as diphenhydramine hydrochloride (for example, Benadryl) or chlorpheniramine maleate (for example, Chlor-Trimeton), may lessen rash, itching, and other symptoms. Your doctor may also suggest corticosteroid medicine to decrease your symptoms. Take these medicines as your doctor tells you.

If you have severe drug allergies:

• Your doctor may give you an allergy kit that contains a shot of epinephrine and antihistamine tablets. Give yourself the epinephrine shot as soon as you feel a reaction starting. Then take the antihistamines. For more information, see:

  Allergies: Giving yourself an epinephrine shot.

  Allergies in children: Giving an epinephrine shot to a child.

• Go to the emergency room every time you have a reaction, even if you are feeling better. Symptoms can develop again even after the epinephrine shot.
• Keep your allergy kit with you at all times. Be sure to check the expiration dates on the medicines and replace them as needed.
• Always wear medical alert jewelry that lists your drug allergies. You can get this type of jewelry at most drugstores or on the Internet.

If you have allergies to many different medicines, be careful when you start any new medicine. The first time you take a new medicine, take it at your doctor's office or at a hospital where you can get immediate treatment if you have a reaction.

What To Think About

People with AIDS or lupus may have more drug allergies than other people. While the reactions are usually not life-threatening, they make treating the disease more difficult.

If you are allergic to one medicine, you may be allergic to other closely related medicines. For example, if you are allergic to penicillin, you may also be allergic to similar antibiotics such as cephalosporins (cephalexin or cefuroxime, for example).