Drug Allergy

A drug allergy occurs when your immune system reacts abnormally to a harmless medication. Although any medication can potentially trigger a drug allergy, some medications are more likely to do so than others.

Unfortunately, it can sometimes be challenging to distinguish between allergic and non-allergic drug reactions since their symptoms can overlap.

However, non-allergic drug sensitivities do not involve the immune system. Regardless, any unexpected drug response that deviates from the listed side effects needs to be evaluated by an allergy specialist to ensure proper treatment.

Our allergist at Juniper Allergy has extensive knowledge and experience in diagnosing and treating drug allergies.

It’s important to note that a drug allergy is not the same as a drug side effect or toxicity. A drug side effect is a well-known reaction listed on the medication label, while drug toxicity results from an overdose.

Symptoms of A Drug Allergy

After taking a medicine for the first hour, the following symptoms may appear:

  • Hives, a skin rash, itching, or swelling
  • Fever
  • Wheezing, having trouble breathing or feeling pressure in the chest
  • Runny nose, postnasal drip, or a feeling of mucus draining into the throat
  • Wet, itchy eyes
  • Anaphylaxis is an uncommon, potentially fatal event that can cause breathing difficulties, body swelling, abdominal discomfort, lightheadedness, reduced blood pressure, a weak but quick pulse, or even unconsciousness.

A delayed drug Days following exposure to a substance, allergic symptoms (though less frequent) may appear.

  • A serum illness
  • Anaemia caused by drugs
  • DRESS stands for drug rash with eosinophilia and systemic symptoms.
  • Nephritis is an infection of the kidneys.

After stopping the drug causing the symptoms, you can still have these delayed drug allergy symptoms.

Causes of Drug Allergy

A drug allergy develops when your immune system interprets a medicine as a potentially dangerous agent. Viruses and bacteria are typical examples of dangerous substances.

But once your immune system determines that a drug is detrimental to your body, it creates specific antibodies that will tell your immune system to attack the chemical.

The chemicals released during this activity bring the symptoms of an allergic reaction. Drug allergies are frequently associated with the following medications:

  • Antibiotics, mainly penicillin and related drugs
  • Non-steroidal anti-inflammatory medications (NSAIDs), including aspirin and ibuprofen
  • Sulfa medicines, such as naproxen sodium, include sulfonamides.
  • Chemotherapy medications used to treat cancer
  • prescription drugs for autoimmune disorders
  • Anticonvulsants

The following medicines are frequently associated with nonallergic drug responses, which feature comparable symptoms that develop independently of the immune system:


  • Aspirin
  • Contrast dyes used in imaging tests
  • Opiates for treating pain
  • Local anesthetics

Diagnosis and Treatment of Environmental Allergies

According to research, drug allergies may be overdiagnosed, leading people to claim drugs they’ve never been allergic to. Due to this, more expensive, inappropriate medications—such as stronger antibiotics for minor infections—are now frequently used.

We at Juniper Allergy can assist you in figuring out whether you have a drug allergy. Your allergy specialist will examine you physically and discuss your medical, allergy, and family history during your visit.

Your allergy specialist will be able to choose the testing method or methods that may be most effective for determining whether you have a drug allergy based on the information you provide. Skin tests, blood tests, patch tests, and oral drug challenges are typical tests.

One or more of these tests may be recommended by your doctor, and the results of the tests typically reveal whether you have a drug allergy or not.

Your test findings are occasionally equivocal, in which case you might have a medication allergy.

Although some patients may find this annoying, keep hope; your doctor can still utilise this information to suggest possible therapy courses and preventative measures.

The degree of your medication allergy and the kind of medicine that triggers your allergic symptoms will determine how it is treated.

Your allergist will probably advise drug avoidance or a desensitisation procedure under medical supervision to prevent symptoms. Small but gradually increasing dosages of the drug are administered over a period of days during a desensitisation treatment until a therapeutic amount can be satisfactorily tolerated.

Next Steps

Our doctor is pleased to see you and answer any questions you may have if you want to talk more about your needs. Call or email us right away to make an appointment.

Let Juniper Allergy help

If you suffer from Drug Allergies our team is happy to answer any questions you may have and discuss your specific treatment needs. You can call (210) 888-1297 or email help@juniperallergy.com to discuss the next steps.
Author: Dr. Amanda Trott, MD
NPI number: 1568653756
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