Parenchymatous Toxicity of Tramadol: Histopathological andBiochemical Study

Objective: The present study was designed to highlight the toxic impact of tramadol on both biochemical and histopathological aspects in rats' liver, kidney and thyroid gland. Methods: The study was performed on fifty healthy adult male albino rats divided into five groups with ten rats each. (Four experimental and control groups). Five rats (negative control) were kept in a quite non stressful environment, provided with food ad libitum and free access to water. Normal saline (1 ml) was given intramuscularly as placebo in the positive control group (n = 5). Experimental groups (II, III, IV and V) were injected with tramadol intramuscularly equivalent to 12.5 mg, 25mg, 50 mg and 300 mg/kg body weight/day respectively for two weeks. Results: The levels of alanine aminotransferase (ALT), Cardiac treponin I (CTnl), Prothrombin time (PT) and partial thromboplastin time (PTT) in all tramadol treated groups showed significant elevation when compared to control. As regards thyroid function tests (T3, T4, and TSH) showed no significant laboratory difference between all studied groups. There was hepatic and renal histopathological changes in tramadol treated rats whose severity varied with doses of tramadol given. Histopathological changes in thyroid tissues were only seen in group treated with tramadol 50 mg/kg and in acute toxicity group. Conclusion and recommendation: Toxic effects of tramadol on parenchymatous organs as liver, kidney and thyroid gland should be kept in mind and taken cautiously in patient complaining from heaptorenal affection or thyroid diseases.