Long-term effects of tramadol on the reproductive function of male albino rats: an experimental biochemical and histopathological study

Abstract Background Tramadol is a commonly abused erotic drug that recently has gained popularity among young men. It is a centrally acting analgesic used to treat moderate to severe pain. This study aimed to evaluate the chronic toxic effects of tramadol on the reproductive system of male albino rats. It was carried out on 60 rats weighing 130–150 g divided into two groups. The first group (control group) included 30 rats and received normal saline 0.9% 1 ml/day orally for 45 days. The second group (tramadol group) included 30 rats and received tramadol 60 mg/kg subcutaneously three times per week for 45 days. Blood samples were obtained from the animals and analysed for serum testosterone, FSH, LH and prolactin levels. Also, the testes were excised and examined for histopathological changes. Results The results revealed that there was a decrease in the serum levels of testosterone (P = 0.009), FSH (P = 0.057) and LH (P = 0.002) and an increase in the serum prolactin level (P = 0.166) in animals treated with tramadol. In addition, histopathological examination revealed distinct abnormal changes compared with the corresponding control group. Conclusion The present study affirms the deleterious chronic toxic effects of tramadol on the reproductive system of male albino rats. It is thus advisable that tramadol should be used with caution with appropriate dose monitoring to avoid its undesirable side effects on male fertility.