drug use evaluation of three widely prescribed antibiotics in a

background: drug utilization studies are helpful in understanding the current practice. we have conducted a retrospective study to evaluate the relevant use of a group of most commonly prescribed antibiotics in a teaching hospital in iran.  the results of this study may be of help for clinicians to improve the patient care. methods: patients who received parenteral ceftazidim, vancomycin and amikacin from december2010 to may 2011 were enrolled in this study. patient’s data including demographic, length of hospital stay, drug allergy, first and final diagnosis were recorded in a predesigned data collection form. american hospital formulary services (ahfs) book were used as a reference for evaluation of study drug indication and dosing according to diagnosis and microbiological culture. defined daily dose (ddd) of each drug extracted from anatomic and therapeutic chemical classification system (atc/ddd) and drug usage data evaluated by calculating the ratio of prescribed drug to its ddd.| results: the ratio of prescribed daily dose to ddd was 0.78, 0.95 and 0.86 for amikacin, ceftazidime and vancomycin respectively. between amikacin group, 43 patients (86%) received drug empirically, the number of empiric treatments for ceftazidim and vancomycin were 45(90%) and 44 patients (88%). the renal function tests (blood urea nitrogen, serum creatinin) were evaluated in 56% of amikacin group, 64% in ceftazidime group and 78% in vancomycin group. conclusion: the results of this study indicate the need to establish continuing medical education (cme) courses for physicians to familiarize them with standards required to use and monitor these agents.