Anti-allergic drugs all have toxic effects. Therefore, if taken for a long time, these toxic effects will "accumulate" and cause greater harm to the human body. Therefore, when taking anti-allergic drugs, do not use one type for a long time. If it exceeds a month, you need to switch to other types of anti-allergic drugs, or use medication when necessary instead of regular scheduled medication.

Also, it is best not to take an anti-allergic drug continuously for more than one month. Taking a drug for a long time will cause many problems. First of all, anti-allergic drugs can easily cause drug resistance. If they are taken for more than a month, their efficacy will decrease and they will not be able to play an anti-allergic role.

It is best to carry anti-allergy medicine with you. Although allergy sufferers will keep some anti-allergy medicines at home in case of unexpected events, this is not enough. Once you notice some signs of allergies, such as sneezing, itchy eyes, runny nose, etc., you need to take anti-allergic medicines immediately. Medications, in this way, can prevent further deterioration of the condition, so it is best to carry anti-allergy medications with you.

Experts particularly remind that there are still some patients who, after taking anti-allergic drugs, find that they have no effect or even worsen their condition. They mistakenly believe that the dose of the drug is not enough, so they increase the dose without authorization, which is very dangerous. Professor Xie pointed out, "The main reason is that many allergy drugs themselves can also cause allergic reactions."

For example, chlorpheniramine, some patients' original allergic symptoms are not relieved after taking the medicine, and skin problems also occur. Reactions such as itching, rash, diarrhea and abdominal pain, and a few patients may even experience abnormalities in the blood picture, manifested as reduced white blood cell count, thrombocytopenia, etc. Anti-allergic drugs that are likely to cause allergies include promethazine, diphenhydramine, etc. It should be noted that drug allergy can be fatal. Therefore, patients taking anti-allergic drugs must not relax their vigilance. Once they find that the drug is ineffective, they should see a doctor immediately and switch to other drugs.

Experts believe that the taking time is different depending on the time when the patient's allergy occurs. If allergy symptoms occur during the day, take the medicine in the morning; if symptoms occur at night, take the medicine before going to bed. Chlorpheniramine can easily cause drowsiness, dizziness, headache, unresponsiveness, etc., so it is best to take it before going to bed.