[건강메신저 메디TALK] ‘Uninvited guest’ drug allergy needs to be tackled with alternative medicine

We use various medicines to treat illness and make it less painful. Or, you take high blood pressure medication to control your blood pressure, and you use anticancer drugs to treat cancer. When you catch a cold, you may take fever reducers or cough medicine to recover more easily. Medicines are mainly used as treatments, but they also include preventive shots to prevent diseases and computed tomography (CT) contrast agents for diagnosis.

Even if you do not have a ‘drug allergy’, you may experience various adverse reactions after taking medicine. Most adverse reactions can be predicted and dealt with by adjusting the dosage. For example, drowsiness that occurs after taking a cold medicine for a runny nose, heartburn that occurs after taking an antipyretic, analgesic, and anti-inflammatory medication, and nausea and vomiting that occur after taking an anticancer drug. When such adverse reactions occur, reduce the dose or replace with a drug with fewer adverse reactions. If absolutely necessary, use the treatment for the adverse reaction and the causative drug together.

Unlike this phenomenon, the difficulty with drug allergies is that it is impossible to predict who, when, and which drug will cause the allergy and how. A drug that was once an ally to both the patient and the doctor unexpectedly turns into an enemy one day and attacks the patient. When this happens, not only the patient, but also the doctor who prescribed the drug, the company that developed the drug, and the pharmacist who instructed the patient in dispensing and taking the medication are in trouble.

The reason drug allergies are unpredictable is because our body’s immune system plays a role in the development. Our bodies are originally designed to recognize and react to ‘really bad things’ such as bacteria and viruses. The problem arises from over-recognition of unnecessary drugs as ‘bad’. At first, there are no symptoms, but after the immune system begins to react, an unexpected allergic reaction suddenly occurs. In the drama ‘Wise Doctor’s Life’, there is a scene where surgery resident Jang Gyeo-ul (Shin Hyun-bin) goes to the emergency room due to anaphylaxis, a rash that occurs after taking menstrual pain medication (antipyretic analgesic and anti-inflammatory medication), swollen face, and a drop in blood pressure. Likewise, drug allergies are something that even doctors cannot predict.

Representative drugs that cause drug allergies are antibiotics, antipyretic analgesics and anti-inflammatory drugs, and CT contrast agents. Depending on which side the immune phenomenon occurs, drug allergies are divided into two types: acute type and delayed type. The representative phenomenon belonging to the acute type is anaphylaxis, and the main causative drugs are antipyretic analgesics and anti-inflammatory drugs, antibiotics, and CT contrast agents. Anaphylaxis is a severe allergic reaction that occurs throughout the body within minutes to hours of exposure to the cause. Delayed reactions include Dress syndrome and Stevens-Johnson syndrome caused by antibiotics or anticonvulsants. This occurs while taking certain medications continuously for several days to several weeks. In this way, drug allergy is a complex disease because even if the same drug is administered, completely different symptoms may occur depending on the immune system response.

If the medicine turns into an enemy and you start having an allergic reaction, you need to get an accurate diagnosis from an expert and make a plan for the future. An appropriate diagnostic method tailored to the immune phenomenon must be selected to find the exact cause and devise countermeasures. For Jang Winter, a medical resident who suffered from anaphylaxis due to menstrual pain medication, not taking antipyretic analgesic and anti-inflammatory medication is not an option. How difficult would life be if you had a tooth extracted because you were allergic to painkillers, or if you had a fever of 39 degrees due to the flu and couldn’t take painkillers. The ultimate treatment goal for drug allergies is to find alternative drugs that can be used safely, identify drugs that can cause similar symptoms, and prevent such incidents from happening again. If you develop an allergy to a life-threatening anticancer drug, in addition to changing the drug, you must also undergo desensitization treatment to reduce allergic reaction.

As various treatments are being developed for many diseases, the number of drug allergies is also increasing. If a suddenly turned ally is pointing a knife at you, please find a drug allergy expert and prepare a strong shield.

[박경희 교수(세브란스병원 알레르기내과)]