To compare the efficacy of dapoxetine hydrochloride for the treatment of primary premature ejaculation when taken on time and on demand.

This study was a randomized controlled study. Patients with primary premature ejaculation diagnosed at the Andrology Outpatient Department of the Second Affiliated Hospital of Xi'an Jiaotong University between September 2018 and June 2019 were included. Inclusion criteria included ①non-homosexual patients aged≥18 years, ②regular sexual partner and rapport relationship with their sexual partner for more than 1 year, ③no serotonin reuptake inhibitors application within 3 months before treatment, ④ejaculated within 2 minutes of penile entry into the vagina that lasts>6 months, ⑤on participation in other similar trials in the past 6 months, ⑥had sexual intercourse≥2 times/week. Exclusion criteria included ①erection hardness score<3 points, ②malformation or dysplasia of reproductive organs, ③genitourinary infection, ④patients with severe heart disease, hypertension, diabetes mellitus, ⑤hypogonadism, ⑥allergy to dapoxetine hydrochloride and excipients, ⑦ patients with moderate or severe liver damage. The enrolled patients were divided into an on-time medication group and an on-demand medication group according to the randomized number table method. Patients took dapoxetine hydrochloride 30 mg/time, once a day, immediately after dinner in the on-time medication group, and the patients took dapoxetine hydrochloride 30 mg/time 2-3 h before intercourse in the on-demand medication group. The latency of intravaginal ejaculation (IELT), the score of the diagnostic tool for premature ejaculation (PEDT), the score of premature ejaculation index (IPE), and the score of anxiety level (SAS) of the two groups were observed within 8 weeks of medication intaking and 8 weeks of medication withdraw.

A total of 136 patients were enrolled, and finally 88 completed the 8 weeks treatment, including 50 patients (73.53%) in the on-time medication group and 38 patients (55.88%) in the on-demand medication group. There was a statistically significant difference between the two groups in terms of patient adherence (P = 0.048). There were no significant differences in pre-treatment IELT [(2.23 ± 1.81) min vs. (1.80 ± 1.51) min], PEDT scores [(16.52 ± 1.54) vs. (16.84 ± 1.59)], IPE scores [satisfaction (32.67 ± 7.36) vs. (32.37±5.90), control (23.31 ± 5.48) vs. (22.97 ± 4.82), pain severity (36.43 ± 3.51) vs. (35.82 ± 3.27)], and SAS scores [(51.80 ± 6.93) vs. (53.82 ± 4.47)] between the on-time medication group and on-demand medication group (P>0.05). After 8 weeks of treatment for patients in the on-time versus on-demand medication groups, the IELT [(5.45 ± 2.64) min vs. (5.01 ± 2.31) min], PEDT scores [(13.68 ± 2.15) vs. (14.92 ± 9.39)], IPE scores [satisfaction (42.58 ± 5.13) vs. (43.39 ± 4.76), control (31.86 ± 4.49) vs. (32.75 ± 5.43), pain severity (62.94 ± 4.07) vs. s (61.22 ± 4.25)], and SAS score [(49.70 ± 4.16) vs. (51.66 ± 4.65)] were not statistically different (P>0.05). However, the differences were statistically significant when compared with those at the initial consultation (P<0.05). After 8 weeks of drug withdrawal, the scores of IELT, PEDT and IPE in the two groups were not significantly different from those before treatment(P>0.05).

Taking dapoxetine hydrochloride on time and on demand can effectively alleviate the symptoms and anxiety of patients with primary premature ejaculation, and the compliance of the on-time medication group was better. Premature ejaculation symptoms recur after long-term discontinuation of the drug.

Premature ejaculation; Dapoxetine hydrochloride; Efficacy; Ejaculatory latency; Compliance