Comparative Study of the Neurotoxic Effects of Pregabalin Versus Tramadol in Rats

Background: In Egypt, both pregabalin and tramadol misuse increased in the last decade. Although many studies have confirmed the neurotoxic effects of tramadol, those of pregabalin are understudied. Aim of the study: evaluation of the neurotoxic effects of pregabalin compared with tramadol.Material and method: Thirty male albino rats were included in this experimental study, and they were randomly allocated into three equal groups; Group I (normal saline), Group II (Tramadol addicted), and Group III (pregabalin addicted). All rats received the commenced drugs for 1 month. Open-field tests were performed on the day of scarification, and after that, cortical samples were taken for immunohistochemical analysis and quantification of dopamine receptors' gene expression.Results: The addicted groups showed a significant decrease in weight gain at the end of the study. Open-field testing showed the upper hand of controls regarding all of the tested parameters. Tramadol has a more negative impact on the locomotor parameters compared with pregabalin. Both drugs induced relatively low dopamine-1 receptors (D1Rs) expression to dopamine-2 receptors (D2Rs), mimicking the schizophrenia model.Conclusion: Both tramadol and pregabalin were associated with neurotoxic effects in male albino rats. These effects were less noticed with pregabalin. It is suggested that long-term abuse may end in psychosis.