Background Antibiotics are among the most frequently prescribed drugs in children. Although antibiotics are mainly used in the primary care, hospitals are considered to be the centre of antimicrobial resistance due to high density of broad-spectrum antibiotic use both in children and adult population.

Purpose To analyse antibiotic prescribing tendencies and their usage in hospitalised children treatment as a first step to improve antibiotic usage at the hospital.

Materials and methods A retrospective, analytic observational study. Evaluated patients were aged 0-18 years and were consecutively admitted to the Infectious diseases unit from January 1^st to February 28^th, 2011. Antibiotic usage was analysed within the following age groups: <1 year, 1-2 years, 2-5 years, 5-12 years, and 12-18 years. For each child, information was obtained from full-text medical charts. The following data were collected: age, gender, weight, diagnosis, used systemic antibiotics (ATC J01), dose per administration, number of doses per day, route of administration, the day of hospitalisation (when antibiotic treatment started), duration of the treatment, number of days spent at hospital, and microbiology data.

Results In total, 609 (307 females and 302 males) of hospitalised children were evaluated. Antibiotics were prescribed for 294 (48%) of patients (134 females and 160 males). The majority of children treated with antibiotics (130; 44%) fell in the group of age between 2 and 5 years. The average duration of the hospital stay was 5.7 days. Respiratory tract infections (pneumonia, bronchitis) were the most common indications for prescribing antibiotic usage. The second most common indication was gastroenteritis (mostly rotavirus aetiology). Ampicillin and cefotaxime were used to treat at least 90% of patients. The parenteral route was used in 97% of indications. In total, there were 5% ‘off-label’ prescriptions (mainly Sulfamethoxazole/Trimethoprim). 97% of prescriptions had a correct dose, but 3% had a lower dose than recommended. During the study period there was no antibiotic prescription that had a higher dose than recommended. Sulfamethoxazole/Trimethoprim was prescribed more often under the recommended minimum dose than other drugs. There was no ‘unlicensed’ or ‘unregistered’ use of antibiotics. 179 (61%) of 294 children received antibiotics based on clinical signs of possible infection, but without any microbiological confirmation.

Conclusions Further analysis of antibiotic prescribing tendencies in hospitalised children treatment and the development of local guidelines for antibiotic use in children treatment should be developed as soon as possible. In addition, physicians and parents should receive additional education.