What are drug allergies?

What are drug allergies?

An allergic reaction to a medicine is refer to as a drug allergy. Mild discomfort to life-threatening illnesses can all exhibit symptoms. Penicillin is the most typical trigger for medication allergies. Similar to penicillin, other antibiotics also commonly lead to drug allergies.

As soon as the medicine enters the body, anaphylactic symptoms start to happen right away. The medicine causes the immune system to react and produce certain IgE antibodies (proteins made by the immune system to fight the drug). We refer to this as “sensitization.”

The body attempts to get rid of medicine when it is taken again by releasing huge amounts of the chemical histamine, which is released by the IgE antibodies. Immune cells assist in fighting the medication during a delayed response.

Which medications most frequently result in an allergic reaction?

Penicillin and other medicines that are comparable to penicillin are the most frequent cause of medication allergies. Other medications (not involving IgE antibodies) that may trigger responses include:

  • Medicine sulfa
  • Anticonvulsants
  • Nonsteroidal medications (like aspirin and ibuprofen)
  • Contrast colour
  • Chemotherapy medications

What signs or symptoms indicate a medication allergy?

Allergy symptoms can range from minor discomfort to potentially fatal illnesses. The stomach distress that many medications might produce is only one of several side effects or intolerances. These signs don’t necessarily point to a genuine medication allergy.

Histamine and other substances may contribute to the following signs and symptoms of an allergic reaction:

  • Hives
  • A skin rash
  • Itchy eyes or skin
  • Congestion
  • Swelling of the neck and mouth

The following are signs of more severe reactions:

  • Having trouble breathing
  • Bluish colour of the skin
  • Blood pressure decline

How are allergies to drugs identified?

A physician must thoroughly examine the patient’s medical history and symptoms in order to identify drug allergies. Your allergist may do a skin test to determine whether you are allergic to an antibiotic like penicillin if you have a suspicion that you are.

Skin testing, however not always possible and is occasionally risky, is not available for all medications. Additionally, your allergist may suggest a “challenge” in certain circumstances (taking the medication again under medical supervision).

Your doctor may suggest using a different, equally effective treatment if you have ever experienced a severe, life-threatening, allergic-type reaction to a particular medication due to the risk involved with a reaction.

Drug allergies: how are they handled?

When treating patients, the main concern is relieving the symptoms:

  • Antihistamines and rarely corticosteroids can often alleviate common symptoms including rash, hives, and itching.
  • Bronchodilators (inhalers), which relieve coughing and lung congestion, may be given.
  • Epinephrine (adrenaline) is often given for more severe anaphylactic symptoms (life-threatening responses, including difficulty breathing or loss of consciousness).
  • Desensitization is sometimes used to treat medication allergies, especially when testing is neither possible nor practical. As long as you keep taking the prescription, this method aims to temporarily enable your body to tolerate allergens.


Always let your doctor know if you have a medication allergy before getting any kind of treatment, such as dental work or surgery. Additionally, it is a good idea to either carry a card that states your medication allergy or wear jewellery (such as a bracelet or necklace). This kind of identification might save your life in an emergency.