Investigation of ejaculatory disorder by silodosin in the treatment of prostatic hyperplasia

BMC Urology Investigation of ejaculatory disorder by silodosin in the treatment of prostatic hyperplasia Koichi Sakata 0 Tatsuo Morita 1 0 Department of Urology, Imaichi Hospital , 381 Imaichi, Tochigi, Nikko-shi , Japan 1 Department of Urology, Faculty of Reno-urology Surgery, Jichi Medical University , 3311-1 Yakushiji, Tochigi, Shimotsuke-shi , Japan Method: The subjects of this study were 91 patients who had been clinically diagnosed to have LUTS/BPH at this hospital, who were administered silodosin at 4 mg twice a day, and who gave response to a questionnaire survey related to ejaculatory disorder. Sexual intercourse and masturbation were regarded as sexual actions in this study. Results: Ejaculatory disorder occurred in 38 (42%) of the 91 silodosin administration cases. Forty (44%) of the 91 patients answered that they carried out sexual actions after oral intake of silodosin. When the investigation was conducted only in those who exercised sexual actions, ejaculatory disorder was observed in 38 (95%) of these 40 patients, indicating a high incidence. When asked if disturbed by the ejaculatory disorder, 29 (76%) of the 38 patients who had ejaculatory disorder answered yes. Oral silodosin was discontinued due to the ejaculatory disorder in 2 (5%) of these patients. On the whole, the discontinuation rate of oral silodosin was 2% (2/91 patients). Conclusion: It was demonstrated that the administration of silodosin induced ejaculatory disorder at a high incidence. Since it is possible that the high frequency of ejaculatory disorder by silodosin may reduce QOL, it is considered necessary to provide sufficient information related to ejaculatory disorder at the time of treatment with silodosin. Silodosin; 1 blocker; Ejaculatory disorder; Adverse reaction; Sexual action - Background Sympathetic nerve 1 receptor has receptor subtypes 1A, 1B and 1D. Recently, the research on 1A receptor subtype has made much progress so that various drugs to treat LUTS by BPH have been commercialized [1,2]. The affinity of tamuslosin hydrochloride to 1A receptor is comparatively high while naftopidil is characterized to have comparatively high affinity to 1D receptor subtype [3,4]. On the other hand, silodosin acts on 1A receptor in a very specific manner [5]. The practical clinical application of silodosin started in Japan in 2006. However, this drug frequently causes ejaculatory disorder as an adverse reaction. The incidence of ejaculatory disorder in the phase III clinical study in Japan is reported as 22.3% [6]. However, this incidence of ejaculatory disorder refers to the incidence in the patients treated with silodosin on the whole without taking the presence or absence of sexual actions (sexual intercourse, masturbation) into consideration. The true incidence of ejaculatory disorder should be calculated by investigating the patients who carried out sexual actions during the administration of 1 blocker. Accordingly, a questionnaire survey related to the ejaculatory disorder was conducted this time in the LUTS/BPH patients under treatment with silodosin to investigate the circumstance of ejaculatory disorder caused by silodosin among the patients who exercised sexual actions. Methods The subjects of this study were 91 patients who had been clinically diagnosed to have LUTS/BPH at this hospital between June 2006 and July 2011, who were administered silodosin at 4 mg twice a day, and who gave response to a questionnaire survey retrospectively (Table 1). In this regard, the standard oral dose of Table 1 Questionnaire survey table * Loose stools and diarrhea. * Nasal congestion. * Light-headed feeling when standing up or changing the posture. * Decreased amount of semen or a feeling different from that in the past at the time of ejaculation. * About ( ) times in (1 month, 3 months, 6 months, 1 year). The following questions are only for those who have carried out sexual actions (sexual intercourse, masturbation) since the start of taking the drug. (1) How do you feel about ejaculation after you started taking the drug? * Feel difference from the condition before taking the drug. If you can explain, please specifically describe the feeling ( ). How often do you feel the difference? * On each time * Approximately on 2 of 3 times * Approximately on 1 of 2 times * On 1 of 3 or more times (2) How is the amount of semen at the time of ejaculation after you started taking the drug? * The amount became decreased * No semen at all (3) If you are aware of the decreased amount of semen or no semen at the time of ejaculation, do you worry about it? * I do not worry and want to continue the medication. * I worry but want to continue the medication. * I worry and want to discontinue the medication silodosin is 8 mg/day in Japan. Sexual intercourse and masturbation were regarded as sexual actions in this study. In the questionnaire survey (Table 1), Question 1 is related to the adverse reactions including ejaculatory disorder after taking oral silodosin, and Question 2 investigates the presence or absence of sexual actions (sexual intercourse and masturbation) and the frequency. Question 3 is targeted at only the patients who exercised sexual actions and had the chances of ejaculation even after taking oral silodosin, more concretely, to investigate the presence or absence of ejaculatory disorder and frequency, changes and prevalence in the amount of semen at the time of ejaculation. The last question was whether or not the patients wished to discontinue oral silodosin because of the ejaculatory disorder. Each of the items including the prostate volume before silodosin administration, the international prostate symptom score (IPSS) and QOL score before and after 4 weeks from administration, were investigated in the 91 patients who responded to the questionnaire. Questionnaires were administered in this hospital and a fixed doctor has completed the questionnaires with interview form. This questionnaire survey was retrospectively performed for 91 LUTS/BPH patients who were administered silodosin for over 4 weeks, and questionnaires were given to patients at the revisit of the time all patients who already been on treatment have been contacted. This research was approved in the ethical committee in our hospital and all patients were consented to this research. As to the statistic analysis, ANOVA, t-test and x2 test were employed, and p<0.05 was handled as significant difference. Results The questionnaire survey was conducted in the patients who had been taking oral silodosin for over 4 weeks from the start. All 91 patients completed the questionnaire survey. As to the background of 91 patients, their age was 55~ 84 years old (mean 66.9 6.9), silodosin administration period was 2 ~18 months (mean 6.7 2.8) and prostate volume was 31 ~94 ml (mean 39 10.3). Figure 1 shows the changes in IPSS and QOL score before and after silodosin administration. Compared with the status before treatment, the IP (...truncated)