Tehran University of Medical Sciences Journal of Pharmaceutical Care 2322-4630 3 1-2 2016 05 30 16 20 EN Rasool Soltani Department of Clinical Pharmacy and Pharmacy Practice, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran. Hossein Vatanpour Department of Pharmacology and Toxicology, School of Pharmacy and Pharmaceutical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Fatemeh Shafiee Department of Pharmaceutical Biotechnology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran. Niloofar Sadeghian Department of Clinical Pharmacy and Pharmacy Practice, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran. 2016 05 28 Background: Opioid drugs are the most effective drugs for the treatment of moderate to severe pain. Rates of opioid use are influenced by a variety of factors. The aim of this study was to determine the pattern of use of parenteral opioid drugs in hospitalized patients in a referral teaching hospital. Methods: In a retrospective study, required data were extracted from medical records of adult patients who had received any parenteral opioid analgesic in the 6-month period from March 2013 to September 2013. The Anatomical Therapeutic Chemical Classification/Defined Daily Doses (ATC/DDD) system method was used for evaluation of opioid analgesic use in patients. Results: The overall usage of parenteral opioid analgesics was 730.51 DDDs with meperidine (Pethidine) having the most amounts of use (588.69 DDDs and 33.23 DDDs/100 bed-days). Overall, the male surgery ward and emergency department had the most amounts of use based on the number of DDDs (445.8 DDDs) and per 100 bed-days (1046 DDDs/100 bed-days), respectively. Methadone use was most in the infectious diseases ward. Conclusion: The trend of parenteral opioid analgesics consumption is increasing in this hospital. Therefore, better adherence to pain treatment guidelines by medical staff is necessary for rational use of these drugs. https://jpc.tums.ac.ir/index.php/jpc/article/view/90 https://jpc.tums.ac.ir/index.php/jpc/article/download/90/74