Abstract: AIM: To investigate clinical usage of drugs for respiratory system diseases. METHODS: The in-hospital records from November 2001 to February 2002 were investigated in a hospital.The usage and utilization of the drugs were analyzed with DDDs.Drug interactions were evaluated with a software (Reasonable Medication System). RESULTS: The frequency of use of antimicrobial accounted for 35 % in total.The other two kinds were anti-asthma drugs and the removing fever of ready-made traditional Chinese medicine.Some unreasonable interactions were found in this investigation. CONCLUSION: In the hospital, the usage of drugs for respiratory system diseases is rational on the whole, but drugs interaction should not been neglected.

Key words: pharmacy, respiratory system disease, frequency of drug use, drugs interaction, drug combination therapy