Drug Utilization Evaluation of Imipenem in an Educational Hospital in Mazandaran Province

Imipenem, a member of the carbapenem class of beta-lactam antibiotics, is a broadly active antimicrobial. Due to indiscriminate use, drug resistance has spread in many hospitals. The aim of this study was to evaluate utilization of imipenem in Imam Khomeini educational hospital in Sari. Over a three-month period from September to November 2010, all patients who received imipenem during hospitalization were included. Demographic data, duration of imipenem therapy, dose, dosage adjustment in renal insufficiency and co-prescribed antimicrobials were extracted from patient's medical files. Recommendations of UpToDate 20.2 and Sanford 2009 were considered as standards of rational imipenem prescribing. Data analysis was performed by SPSS 17 software. A total of 100 patients with a mean age of 51.4±21.4 were enrolled in the study. Dose and duration of imipenem therapy were appropriate in 64 (64%) and 50 (50%) patients, respectively. In 83 (83%) cases, empiric antibiotic therapy was initiated within the first day of admission which included imipenem in 31 patients (37%). All patients received imipenem as empiric therapy. The most common co-prescribed antimicrobial agent with imipenem was vancomycin (66 cases). Imipenem was administered by consult of an infectious specialist just in 30% of patients. 14 imipenem prescriptions (14%) required dosage adjustment according to the patient's renal function, whereas it was performed only for 5 (35%) patients. Culture tests were carried out for 29 (29%) cases. High rate of empiric prescription of imipenem without considering culture and antimicrobial susceptibility results, lack of attention to dosage adjustment in renal insufficiency and initiation of antimicrobial therapy at the time of admission were the most important aspects of irrational use of imipenem that observed in this study. Providing a reliable culture/sensitivity setup and prescribing of imipenem based on a specific guideline are recommended.