If you take loratadine tablets for allergy and it doesn’t work, you are not detached from the allergen, you are not sensitive to the drug, or you have made a mistake in using the drug, so you should detach yourself from the allergen and use other drugs to treat it. 1. not from the allergens: allergy is a kind of allergic reaction, is caused by contact with allergens, if you take loratadine tablets do not work, is considered to be not from the allergens, should go to the hospital to find out the allergens, and then away from the allergens. 2. insensitive to drugs: loratadine is the second generation of antihistamines, patients may not be sensitive to this class of drugs, choose the first generation of antihistamines, such as Benadryl, if the effect of the drug is still not obvious, the symptoms of the more serious can also choose glucocorticosteroid drugs, such as hydrocortisone, prednisone and so on. 3. medication error: for some disease symptoms, such as viral infections after the rash, this situation and allergies after the appearance of the rash is more similar, the wrong medication will not have the effect, you need to stop using drugs, replace the antiviral drugs, such as ganciclovir, vasiclovir and so on. Allergies take loratadine tablets do not work should be timely to go to the hospital, under the guidance of the doctor to choose the appropriate method, the above drugs should be used in accordance with medical advice.