Comparison of urine trace element levels in tramadol addiction alone and its co-abuse with cigarette and opium in Western Iran.

Tramadol is an opioid pain medication used to treat moderate to severe pain. Tramadol consumers tend to co-abuse some other substances such as opium, cigarettes, alcohol, and cannabis and each of these substances may impair trace elements homeostasis in the body. Therefore, this case-control study aimed to compare the urinary concentration of some essential and toxic elements in tramadol addiction alone and its co-abuse with cigarette and opium in Western Iran. For this purpose, urine samples were collected in two groups of tramadol (n = 72) and control subjects (n = 62) from March to November 2020. The case group was divided into three groups: tramadol alone, tramadol + opium, and tramadol + cigarettes. Moreover, ICP-MS (Agilent 7900) was used to measure trace element concentrations in the urine samples. Based on our results, Fe was the only element markedly higher among controls as compared to tramadol users (p < 0.001). Moreover, the concentration levels of As appeared to be the same among both groups, but the levels of other elements including Ca, Cd, Cr, Mn, Cu, Zn, Co, Ni, Se, and Pb were all significantly higher among tramadol users as compared to control group. The rank-based regression analysis illustrated that no contribution of sex and age effect was found by the regression model on the levels of all 12 studied elements. While, smoking was found to affect the levels of Fe (β = 0.163, P = 0.025) and Co (β = 0.411, p < 0.001) so that smoking reduced Fe levels but elevated Co concentration levels. Abuse of tramadol along with cigarettes and opium increased the concentration of some heavy metals in urine samples compared to the control group. However, these results showed no significant effect of age, sex, smoking habit, and amount of tramadol usage on the levels of trace elements.