Effect of pentoxifylline on semen parameters, reproductive hormones, and seminal plasma antioxidant capacity in men with idiopathic infertility: a randomized double-blind placebo-controlled study.

OBJECTIVE: To determine the safety and efficacy of oral pentoxifylline (PTX) administration in improving semen parameters in infertile men with idiopathic OAT.

PATIENTS AND METHODS: The study included 254 infertile men who underwent double-blind therapy with 400 mg PTX (Apotex Inc., Toronto, Canada) twice daily (group 1, n = 127), or similar regimen of placebo (group 2, n = 127). The study consisted of a 4-week screening phase, a 24-week treatment phase, and a 12-week treatment-free period. The effects of treatment on semen parameters, serum hormones including testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and inhibin B, seminal plasma catalase-like and superoxide dismutase (SOD)-like activity, and acrosome reaction test were evaluated.

RESULTS: A significant increase in sperm concentration (mean value, 26.4 ± 4.6 × 10(6)/ml vs. 16.2 ± 3.4 × 10(6)/ml), sperm motility (mean value, 35.8 ± 4.2% vs. 26.4 ± 2.4%), and sperm with normal morphology (mean value, 25.4 ± 4.3% vs. 17.4 ± 4.2%) was observed after PTX administration when compared with baseline (all P = 0.001); in contrast, a subtle decreased values were observed after placebo (median values, 16.4 ± 4.1 × 10(6)/ml vs. 16.7 ± 3.6 × 10(6)/ml, P = 0.1; 25.7 ± 3.6% vs. 26.8 ± 2.5%, P = 0.08; and 16.9 ± 4.1% vs. 17.6 ± 4.4%, P = 0.08, respectively). Mean SOD-like and catalase-like activity in the semen of PTX group was significantly greater than in the semen of placebo group (46.4 ± 2.4 vs. 36.3 ± 1.3 U/ml and 371 ± 44 vs. 301 ± 14 U/ml, respectively, both P = 0.003). The acrosome reaction was observed to be increased in PTX group (P = 0.01). Levels of reproductive hormones were also affected.

CONCLUSIONS: PTX administration significantly improves semen parameters in infertile men with idiopathic OAT.