Objective To investigate the irrational use of montelukast sodium tablets in the outpatient emergency department of a hospital

analyze the causes of its use

and correct the irrational use of montelukast sodium tablets in clinical practice. Methods A total of 2 106 electronic prescriptions of montelukast sodium tablets prescribed from August 2020 to July 2021 were selected by the Hospital Information System（HIS） system

and the existing problems of irrational use of montelukast sodium tablets and the distribution of drug-prescribing departments were statistically analyzed. Results Of the 2 106 prescriptions selected

1 121（53.23%） were irrational prescriptions

mostly characterized by off-label drug use

of which 1 096（97.77%） were off-label drug use

mainly prescribed by the respiratory medicine clinics

community general medicine clinics

and neurology clinics. Conclusion The irrational use of montelukast sodium tablets in our hospital is mainly off-label drug use. The hospital should strengthen the training of doctors on rational drug use. Pharmacists should effectively use modern tools to strengthen the supervision of rational drug use and correct the irrational off-label drug use in clinical practice.