Polycytidyne (generally referred to as polycytidyne injection) has certain antiviral efficacy when applied externally, and can be used in the treatment of viral keratitis, herpes simplex, and the adjuvant treatment of chronic viral hepatitis. 1. Polyinosinic acid injection is made of sterilized aqueous solution containing double-chain polyinosinic acid polycytidylic acid polymer, which can promote antibody formation, stimulate phagocytosis by macrophages, and induce interferon, and it has a better therapeutic effect on diseases caused by a variety of viruses, and it can be used in the treatment of viral keratitis, herpes simplex and the adjuvant treatment of chronic viral hepatitis. 2. It is forbidden for pregnant women, lactating women, and those who are allergic to this product. A few patients may have the adverse reaction of low fever after using the drug. Note that if allergic reaction occurs, or fever is produced after injection, which cannot disappear by itself after two days, the drug should be stopped immediately. It is recommended that patients go to the hospital for consultation and treatment under the guidance of specialists, and should not blindly use the drug on their own.