1. ABSTRACT Antibiotic Utilization Study on Acute Exacerbation of Chronic Obstructive Pulmonary Disease (A Study in Man and Woman Pulmonary Ward Dr. Soetomo Hospital Surabaya) Dewi Wara Shinta Backgrounds. Exacerbations of chronic obstructive pulmonary disease (COPD) are of major importance in terms of their prolonged detrimental effects on patients and the acceleration in disease progression. Bacterial respiratory tract infections play an important role in the pathogenesis of COPD exacerbations. Antibiotics appear to have a beneficial effect in patients experiencing an acute exacerbation of COPD. Objective. The aim of this report was to document the pattern of antibiotic prescribing in acute exacerbations of chronic obstructive pulmonary disease (COPD), to examine type, dosage, route, duration of antibiotics and its related to clinical and laboratory data, and to identify potential Drug Related Problems (DRP). Methods. All episodes of acute exacerbation of COPD in Dr. Soetomo Hospital Surabaya in the period January 1st to June 30th 2006, were identified. Case notes were reviewed retrospectively from medical records. Symptoms, clinical and laboratory data, microbial cultures and initial antibiotic therapies were recorded. Data from a total of 46 patients were analyzed using descriptive analysis. Results. Levofloxacin and cefotaxime was the most frequently prescribed antibiotic in 26 patients (56,5%). From 46 patients, 30 patients (65,2%) were switched to other type of antibiotic, 14 patients (30,4%) were given antibiotic as monotherapy, and 6 patients (13,0%) were given antibiotic as combination. Drug interactions most frequent were identified between ciprofloxacin and aminophylline (18 pastient). Conclusions. The pattern of antibiotic prescribing (type, dosage, route, frequency) was appropriate according to the guideline. The duration and switch of antibiotics depend on patient clinical conditions. Keywords : Drug Utilization Study (DUS), antibiotics, AECOPD