Usually encountered drug allergy is needed to gradually exhaust, the time will be longer, usually from a single drug, a small dose to start trying, it is recommended that you find an experienced doctor or hospitalized to try the drug, it is not safe to try at home, the time will be a lot longer than this doctor said, be patient, can not be in a hurry, as to whether or not it will lead to resistance to the drug, and drug allergy caused by the adverse reactions compared to this is not the main problem at the moment, because, the induction of resistance to the drug is just a possibility, while the drug allergy, a serious one can be fatal.