Neither all anti-inflammatory drugs nor all doses are effective in accelerating the antidepressant-like effect of fluoxetine in an animal model of depression

Abstract Introduction Non-steroidal anti-inflammatory drugs (NSAIDs) have been studied as possible adjunctive therapy in the treatment of depression. However, administering NSAIDs to increase the effectiveness of antidepressant has yielded inconsistent results. Methods We evaluated the effect of the co-administration of fluoxetine (5 mg/kg) and flurbiprofen (5 mg/kg) or fluoxetine (5 mg/kg) and celecoxib (5 mg/kg) in the chronic escape deficit (CED) model of depression after 7 days of treatment. The co-administration of fluoxetine plus acetylsalicylic acid (ASA, 45 mg/kg i.p.) was used as a positive control. Moreover, we tested the behavioral effect of different doses (45, 22.5, and 11.25 mg/Kg i.p.) of ASA as potentiating agent of the effect of fluoxetine in the same paradigm. Results Our study showed that only the co-administration of ASA with fluoxetine was able to revert the stress-induced condition of escape deficit after 7 days of treatment, and that the amplitude of the antidepressant-like effect of ASA was dose dependent. In the same experimental conditions, celecoxib with fluoxetine only partially resolved the stress-induced impaired behavior while flurbiprofen/fluoxetine cotreatment was ineffective. Limitations Our study is still exploratory, more doses, longer treatment regimens, and different behavioral outcomes must be investigated to draw a clear conclusion. Conclusion Our results further stress the importance of the type and dose when NSAIDs are associated with antidepressants to ameliorate a clinical response.