BACKGROUND: This study aimed to investigate the association between changes in serum 5-hydroxy tryptamine (5-HT) concentrations and improvement in clinical symptoms in primary premature ejaculation with paroxetine treatment.

MATERIAL AND METHODS: A total of 142 men aged 18–65 years with a history of lifelong premature ejaculation and an intravaginal ejaculation latency time (IELT) <120 s were included in this study. Patients were divided into 3 groups according to IELT: IELT ≤30 s (group A), (IELT >30 s and ≤60 s (group B), and IELT >60 s and <120 s (group C). Patients in the 3 groups were administered paroxetine hydrochloride 20 mg/d for 8 weeks. Blood samples were obtained from the candidates in the screening period and after 8 weeks of treatment. Plasma 5-hydroxy-tryptamine (5-HT) concentrations were measured by enzyme-linked immunosorbent assay.

RESULTS: Reliable data from 125 patients were obtained. There were 41 patients in group A, 40 in group B, and 44 in Group C. IELT and serum 5-HT concentrations were significantly improved in the 3 groups after treatment (all P<0.001). The mean change and fold increase in IELT and the mean change in serum 5-HT concentrations in group A were significantly higher than those in groups B and C (all P<0.001). The mean change and fold increase in IELT and the mean change in serum 5-HT concentrations in group B were significantly higher than those in group C (all P<0.001). Significantly more patients in group A achieved clinical benefits than those in groups B and C (P<0.001).

CONCLUSIONS: Improvement in serum 5-HT concentrations has obvious association with primary premature ejaculation symptom improvement with paroxetine use.

Keywords: Adolescent, Biomarkers - blood, Ejaculation - physiology, Linear Models, Paroxetine - therapeutic use, Premature Ejaculation - physiopathology, Serotonin - blood, Serotonin Uptake Inhibitors - therapeutic use, Time Factors, young adult