Skip to content

Allergies Health Center

Font Size
A
A
A

Allergy or Side Effect?

Many people think they have a drug allergy, but they don't -- they've had a bad reaction to the drug. Only 6% to 10% of all drug reactions are drug allergies.

Does it matter? It does. Here's how to tell the difference.

Recommended Related to Allergies

Allergy Tips: Your Outdoor Exercise Checklist

If you have allergies, you might feel like outdoor exercise detracts from your health more than it adds. Exercise is supposed to make you feel good. But if a quick jog or a bike ride leaves you wheezing, sneezing, and feeling miserable for hours afterwards, how healthy can it be? But all of us -- allergic or not -- need to exercise regularly for our overall health. And the good news is that you can, even if you're exposed to outdoor allergens. "People with allergies and asthma should be able to...

Read the Allergy Tips: Your Outdoor Exercise Checklist article > >

Understanding Drug Allergies

When you're allergic to a drug, your immune system overreacts. It treats the medication like a dangerous foreign invader.

When your body senses the drug, it sends out special cells. They release chemicals to drive the substance out of your body. These chemicals can cause hives, swelling in your face, and tightened airways.

You won’t have an allergic reaction the first time you take a drug. Your body has to recognize the drug, which happens when you take it the second time. By then, your body is primed to attack.

Non-Allergic Drug Reactions

In a non-allergic reaction, your immune system isn't the cause of the reaction. Instead, the drug may be interacting with another drug you’re taking. Or it may have an unexpected effect on your body. You can have a bad reaction to a drug the very first time you take it.

Non-allergic reactions to drugs can be just as dangerous – or as mild -- as true allergies. They can even cause many of the same symptoms:

Some common drugs that tend to trigger non-allergic drug reactions include:

Some drugs -- like aspirin -- cause non-allergic reactions in some people and true drug allergies in others.

What to Do for a Drug Reaction

If you have a non-allergic adverse reaction to a drug, you can:

  • Ask your doctor about changing your dose. Simply taking less can sometimes reduce many side effects.
  • Switch drugs. You may only have an adverse reaction to one drug. Another one in the same class might work well and not cause problems.
  • Protect yourself. If you know you react badly to a drug, take care. Make sure that all your health care providers know about it. You may want to get medical ID jewelry -- like a bracelet or necklace -- so that others can know about your drug reactions in an emergency.

WebMD Medical Reference

Reviewed by David T. Derrer, MD on December 05, 2014

Today on WebMD

man blowing nose
Make these tweaks to your diet, home, and lifestyle.
Allergy capsule
Breathe easier with these products.
 
cat on couch
Live in harmony with your cat or dog.
Woman sneezing with tissue in meadow
Which ones affect you?
 

blowing nose
Article
woman with sore throat
Article
 
lone star tick
Slideshow
Woman blowing nose
Slideshow
 

Send yourself a link to download the app.

Loading ...

Please wait...

This feature is temporarily unavailable. Please try again later.

Thanks!

Now check your email account on your mobile phone to download your new app.

cat lying on shelf
Article
Allergy prick test
VIDEO
 
Man sneezing into tissue
Assessment
Woman holding feather duster up to face, twitching
Quiz