Evaluation of effect of fluoxetine and allopurinol in behavioral model of depression in rats

Depression is a common mental illness worldwide. Chronic diseases can lead to depression. Assessment of drug interactions comes to the fore when managing treatment of patients with comorbid disease. In this study forced swimming test which is one of the most commonly used behavioral tests for antidepressants in rodents was used. Antidepressant effect of allopurinol, used in chronic gouty arthritis, was assessed. Antideprressant effect of fluoxetine, a selective serotonin reuptake inhibitor, and allopurinol combination was also assessed. Thirty two Wistar Albino male rats were divided into four groups (control, fluoxetine 10 mg/kg, allopurinol 50 mg/kg, allopürinol 50 mg/kg + fluoksetin 10 mg/kg, n=8 per group) and forced swimming test was performed before and after 14 days drug administration. Antidepressant activity of allopurinol was found to be similar to fluoxetine such decrease in immobility and increase in swimming time. However, in this experimental study, we found no statistically significant difference in antidepressant effects between combined therapy and single drug therapy. This is the first experimental study to investigate antidepressant-like effect of combination of fluoxetine and allopurinol. Unmeasured of plasma and cerebrospinal fluid levels of serotonin and 5-hydroxyindole acetic acid and implementation of fixed drug dose are the limitations of this study. Further studies are needed to show elucidation of the mechanism of drug interaction between fluoxetine and allopurinol and the effect of combined use of different doses.