The fact that antiviral drugs work well in the first month and then become less effective in the second month may be related to the development of drug resistance and an exacerbation of the disease. When antiviral drugs show a decrease in efficacy in the second month of treatment, the first consideration is the development of drug resistance. When the virus in the body develops antibodies to the same drug over a long period of time, a decrease in the effectiveness of the drug occurs, which is called drug resistance. In addition, it may be due to the aggravation of the disease. If the drug is not targeted to kill the virus, it may have some effect at first, but as the virus continues to multiply, the viral load in the body rises and the condition worsens. At this point, the effect of continuing to use the drug obviously deteriorated, you need to consult a doctor in a timely manner, drug sensitivity tests and other tests, under the guidance of the doctor to carry out treatment.