Tramadol Induced Organ Toxicity via Oxidative Stress: A Review on Current Evidences

Background: Tramadol is a synthetic opioid-like centrally acting analgesic used for moderate to severe pain management in a diversity of diseases. Numerous investigations have confirmed the association between tramadol use and increased levels of oxygen-free radicals. Mass production of reactive oxygen species produces secondary toxic compounds which could damage the internal components of the cell and ultimately causes organ damage. With the growing trend of tramadol abuse and the increasing reports of poisoning, abuse and mortality due to this drug, the present study was designed to review the animals and human studies about the effects of acute and chronic exposure of tramadol in inducing organ toxicities through oxidative stress. Methods: Pubmed, Google Scholar and Scopus bibliographic databases were searched for studies investigated the oxidative stress as mechanism of toxicity by tramadol. A manual search of reference lists of the retrieved articles was conducted. Data were collected from 2000 to 2021 (up to June). Results: From 28 articles about experimental and human studies of TR induced oxidative stress organ damage which included in this review, occurrence of lipid peroxidation, alteration in the levels of total antioxidant capacity and other oxidative stress biomarkers in many organs such as brain, liver, kidney, adrenal and lung in the experimental studies of tramadol exposure have been observed. Conclusion: Oxidative stress could be considered as one of the most important toxic mechanisms in tramadol-induced tissue damage.