Abstract: Objective To investigate the clinical use and safety of oseltamivir phosphate, analyze the characteristics of its adverse drug reactions (ADR), and provide reference for rational use of drugs. Methods Data on the use of oseltamivir phosphate in our hospital between February 2016 and February 2018 was retrospectively analyzed in terms of indications, use of drugs, usage and dosage, combined use of drugs and adverse reactions. The rationality and safety of drug use was highlighted. The relationships between adverse reactions and age, allergy history, underlying diseases and combined medication were explored to identify the risk factors. Results There were a total of 1 795 adult patients and 3 199 children who took oseltamivir phosphate. As far as the therapeutic use was concerned, there were 1 481 cases (82.5%) in the adult group, and 2 602 cases (81.3%) in the child group. This drug was prescribed mainly for upper respiratory tract infections, bronchitis and pneumonia, but 767 of these cases were diagnosed with influenza virus infection via virology examination, and the rest were suspected influenza cases or clinically diagnosed cases of influenza. As for preventive medication: the adult group consisted of 314 cases (17.5%), compared with 597 cases (18.7%) in the child group. A lack of indications related to preventive medication was found. Administration started within 48 hours of onset of influenza symptoms, with 109 cases (79.0%) in the child group, and 169 cases (60.1%) in the adult group, Drug usage and dosage, courses of treatment were up to standards, but combined medication was not well-grounded. There were 106 cases of adverse drug reactions, but there was no case of serious adverse drug reactions. Statistical analysis showed that the rate of adverse drug reactions was related to the age of patients and the number of types of combined drugs. Conclusion Excessive use of preventive drugs and inappropriate indications have been found in the clinical use of oseltamivir phosphate. This drug is quite safe and the main adverse reactions involve the digestive system, but the age of patients, combination of drugs and allergy may be regarded as the main risk factors for adverse reactions. The safety of drug use in elderly patients and children has become a concern.

Key words: qseltamivir phosphate, influenza, rational use of drugs, adverse drug reaction