Pentoxifylline as a Novel Add-on Therapy for Major Depressive Disorder in Adult Patients: A Randomized, Double-Blind, Placebo-Controlled Trial

Abstract

Background Evidence indicates an association between immune dysregulation and major depressive disorder (MDD). Pentoxifylline (PTX), a phosphodiesterase inhibitor, has been shown to reduce pro-inflammatory activities. The aim of this study was to evaluate changes in depressive symptoms and pro-inflammatory markers after administration of PTX as an adjunctive agent to citalopram in patients with MDD. Methods One hundred patients were randomly assigned to either citalopram (20 mg/day) plus placebo (twice daily) (n = 50) or citalopram (20 mg/day) plus PTX (400 mg) (twice daily) (n = 50). The Hamilton Depression Rating Scale-17 (HAM-D-17) scores at baseline, weeks 2, 4, 6, 8, 10, and 12 and serum levels of interleukin1-β (IL-1-β), tumor necrosis factor-α, C-reactive protein, IL-6, serotonin, IL-10, and brain-derived neurotrophic factor (BDNF) at baseline and week 12 were evaluated. Results HAM-D-17 score in the PTX group significantly reduced in comparison to the control group after weeks 4, 6, 8,10, and 12 ((LSMD): − 2.193, p = 0.021; − 2.597, p = 0.036; − 2.916, p = 0.019; − 4.336, p = 0.005; and − 4.087, p = 0.008, respectively). Patients who received PTX had a better response (83 %) and remission rate (79 %) compared to the placebo group (49 % and 40 %, p = 0.006 and p = 0.01, respectively). Moreover, the reduction in serum concentrations of pro-inflammatory factors and increase in serotonin and BDNF in the PTX group was significantly greater than in the placebo group (p < 0.001). Conclusion These findings support the safety and efficacy of PTX as an adjunctive antidepressant agent with anti-inflammatory effects in patients with MDD.