Drug Allergy

A drug allergy is the abnormal reaction of your immune system to a medication. Any medication — over-the-counter, prescription or herbal supplement can cause an allergic reaction. 


Drugs commonly linked to allergies include:

  • Antibiotics, such as penicillin

  • Pain-relievers, such as aspirin, ibuprofen (Advil, Motrin IB) and naproxen sodium (Aleve)

  • Chemotherapy drugs for treating cancer

  • Medications for autoimmune diseases, such as rheumatoid arthritis

Symptoms include:

  • Skin rash

  • Hives

  • Itching

  • Fever

  • Swelling

  • Shortness of breath, wheezing

  • Runny nose, itchy, watery eyes

  • Anaphylaxis - a rare, life-threatening reaction to a drug allergy


Signs and symptoms of a serious drug allergy often occur within an hour after taking a drug. Other reactions, particularly rashes, can occur hours, days or weeks later.



If you have a drug allergy, the best prevention is to avoid the problem drug. 

Steps you can take to protect yourself include the following:

Inform health care workers. Be sure that your drug allergy is clearly identified in your medical records. Wear a medical alert bracelet that identifies your drug allergy.



Depending on your reaction and if your reaction to medication has been more than 5 years ago, you may no longer be allergic to the drug. Research has suggested that drug allergies may be overdiagnosed. Misdiagnosed drug allergies may result in the use of less appropriate or more expensive drugs. 


Dr. Offengenden will focus on the details of your reaction to medication. These details will guide testing and treatment of the medication allergy.