What is drug hypersensitivity?
Medications can cause unwanted reactions in many ways. Sometimes, it’s a direct effect of the drug on the body. Drug hypersensitivity reactions occur when the immune system responds to a medication or to the biologic products that result when the body breaks down a medication. In some cases, the immune system tries to attack the substance, causing symptoms of the drug reaction. Drugs also can cause allergic reactions similar to those caused by bee stings or other allergenic substances. People who have a family history of allergic diseases may be more likely to have drug allergy, but are not at greater risk to develop non-allergic types of reactions. Fortunately, a family history of allergy to a particular drug does not increase a person’s chance of being allergic to that same drug. A person must have a previous exposure to a drug in order to have a true allergic reaction to it. Such reactions most often occur when a drug is administered intravenously or by injection, delivery methods t
