Drug Allergy

What is Drug Allergy?

When a person develops a drug allergy, their immune system produces an abnormal reaction to a certain medication. It is often unknown that someone is allergic to a substance until after they show a negative reaction to it. Drug allergies are very common, and they are generally more likely to occur in older adults and seniors. They also show up more often in people with a personal or family history of other allergies, those who are frequently exposed to a drug, and when an individual has an illness that makes them more prone to drug allergies. Young children can also develop reactions, but it does not happen quite as often.

Drug allergies are not the same as experiencing the known side effects of medications. They are also very different from drug overdoses and toxicity. Most of the time, allergic reactions are mild and little more than a nuisance. However, in some cases, the allergy is so severe that it can become a life-threatening situation requiring immediate medical intervention.

What are the Symptoms of Drug Allergy?

Some medications are more likely to create an allergic reaction than others.

Symptoms include

  • Rash
  • Hives
  • Fever
  • Nausea
  • Itchiness
  • Swelling
  • Wheezing
  • Watery eyes
  • Runny nose

When symptoms become severe or life threatening, the patient is increasingly likely to experience shock, anaphylaxis, or coma. Without prompt medical attention, such allergic reactions could ultimately lead to death.

How is Drug Allergy Treated?

The easiest way to treat a drug allergy is to avoid the allergen altogether.

Treatment includes

A doctor might direct discontinued use of whatever medication is causing the reaction and prescribe something else in its place. If that cannot be done, and if symptoms are mild, other medicines like antihistamines or steroids can reduce allergic reactions. Drug desensitization may also be used to see if the allergy can be remedied. Patients with more severe reactions may require epinephrine or bronchodilators.

Last Reviewed:
September 20, 2016
Last Updated:
September 06, 2017