The effect of methadone, buprenorphine, and shift of methadone to buprenorphine on sperm parameters and antioxidant activity in a male rat model

Methadone and buprenorphine are two widely used substances for opioid-based detoxification. The aim of the present study was to examine the effects of buprenorphine and methadone on the redox status of testicular tissue, sperm parameter analysis, and hormonal changes in a rat model. A total of 40 male Wistar rats (220–250 g) were randomly divided into four groups: methadone, buprenorphine, shift of methadone to buprenorphine, and control groups. At days 21 and 42 post-treatment, the animals (n = 5 for each time) were deeply anesthetized, blood sera were isolated, and testes of the rats were dissected out. The levels of blood total testosterone (TT), free testosterone (FT), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) as well as antioxidant enzymes activity in the testicular tissue were measured. Sperm parameters, including sperm viability, motility, and count, were calculated and compared between the groups. Both buprenorphine and methadone treatments induced oxidative stress, suppressed sperm parameters, and resulted in sexual hormone dysfunction compared with the control group. The highest levels of alterations were detected in the shift group. In conclusion, methadone and buprenorphine enhanced testicular oxidative stress, suppressed blood levels of sexual hormone, including LH, FSH, TT, and FT, and resulted in suppressed sperm parameters. There were no significant differences between methadone and buprenorphine treatments in terms of their adverse effects on sperm parameters and antioxidant activity. However, shift of methadone to buprenorphine resulted in the worst adverse effect in the male reproductive system in the rat model.