MCQ Detailed View

When a drug is introduced into the body, it is usually processed and used to treat a medical condition without causing harmful reactions. However, in some cases, the immune system mistakenly identifies a drug as a harmful substance and triggers an abnormal response. This reaction is known as a drug allergy.

A drug allergy is an abnormal, hypersensitive immune response to a medication. When the immune system detects a drug as a “foreign invader,” it produces antibodies (such as Immunoglobulin E) against it. This leads to the release of chemicals like histamines, causing symptoms such as skin rashes, itching, hives, swelling, fever, or even severe reactions like anaphylaxis, which can be life-threatening if not treated immediately.

This is different from drug resistance, where bacteria or other microorganisms become resistant to the effects of an antibiotic or drug over time. It is also different from super infection, which occurs when prolonged antibiotic use disrupts normal microorganisms, allowing harmful microbes to overgrow.

Common drugs that can cause allergic reactions include antibiotics like penicillin, pain relievers like aspirin and ibuprofen, certain vaccines, and chemotherapy agents. The severity of an allergic reaction can vary from mild skin irritation to severe breathing difficulties and organ complications.

Doctors often conduct allergy tests or review patient history before prescribing medications known to trigger allergies. In case of an allergic reaction, the first step is to discontinue the drug immediately and administer appropriate treatment such as antihistamines, corticosteroids, or epinephrine in severe cases.

Thus, when the immune system reacts abnormally to a drug, it is medically termed a drug allergy, making option C (Allergy) the correct answer.