A drug reaction is defined as any harmful or undesirable reaction that occurs at doses used for diagnosis and treatment. Drug reactions are common in clinical practice. Drug allergy, on the other hand, is a type of unpredictable drug reaction that occurs due to hypersensitivity reactions mediated by the immune system through various mechanisms. It is not very common, but it should be taken very seriously as it can result in death. In this article, we have written about the differences between drug allergy and drug reaction and what they are.
Drug Reaction
A drug reaction can be defined as any harmful or undesirable reaction that occurs at doses used for diagnosis or treatment. Drug reactions are common in daily clinical practice and affect 15-25% of patients; Serious reactions occur in 7-13% of patients.
Drug reactions are classified as either predictable reactions that can occur in any (type A) or unpredictable reactions that occur only in susceptible individuals (type B).
Predictable reactions are the most common type of drug reactions and are usually dose dependent and related to the known pharmacological effects of the drug (eg, side effects, overdose, drug interactions). Reactions such as palpitation of breath-taking drugs may occur.
Unpredictable reactions occur in approximately 20-25% of patients who experience drug reactions; These reactions are generally unrelated to the chemical pharmacological effects of the drug as we know it.
Drug Allergy
Drug allergy is a type of unpredictable drug reaction that occurs due to hypersensitivity reactions mediated by the immune system through various mechanisms. It accounts for 5-10% of all drug reactions. Drug allergies are not common, but drug reactions, that is, undesirable effects of drugs, are seen as drug allergies, so they may occur more frequently. Drug allergies are just one of the diseases that occur due to drugs. Not every drug reaction should be called an allergy. It is appropriate to diagnose drug allergy after the necessary tests are done by allergy specialists. Drug allergies account for a small portion of all drug reactions. However, it should be taken very seriously as it can sometimes result in death.
Drug allergies not only affect the patient’s quality of life, but can also delay or prevent treatment, lead to the use of less effective alternative drugs, unnecessary investigations, and even death. Determination of drug allergy is difficult due to different complaints and clinical manifestations. Therefore, if a drug-induced allergic disorder is suspected, it is recommended to consult an allergist experienced in the diagnosis and treatment of drug allergy.
