Tehran University of Medical Sciences Journal of Pharmacoeconomics and Pharmaceutical Management 2383-4498 1 1/2 2015 10 05 1 5 EN Rokhsareh Aghili Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran. Amir Farshchi Department of Pharmacoeconomics and Pharmaceutical Administration, School of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran. Mahdi Shiri Department of Toxicology, School of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran. 2015 10 05 2015 10 05 For the treatment of pain, opioids are the main analgesic approaches. Opioid therapy involves the use of either weak or strong opiates, and both are often prescribed in conjunction to adequately control acute pain. Strong opiates often have additional routes beyond oral administration. Poor understanding of opioids and concerns about governmental retaliation for prescribing opioids can lead to treatment failure. Desired goal in handling of patients with chronic pain is achieving and sustaining an acceptable quality-of-life. In this narrative review, we discuss classifying and clinical use of opioids.   https://jppm.tums.ac.ir/index.php/jppm/article/view/1 https://jppm.tums.ac.ir/index.php/jppm/article/download/1/1