Prostate Drug May Lead to Sexual Troubles

Enlarged prostate may benefit from silodosin but ejeculation trouble may follow

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Silodosin (Rapaflo) is used to treat enlarged prostate, or benign prostatic hyperplasia (BPH). The drug, however, may trigger an ejaculatory disorder.

Patients with enlarged prostates often have painful and/or frequent urination. Often, the urination stream can be weak.

Silodosin relaxes the muscles of the bladder and prostate, relieving symptoms of BPH. A recent study found that a high incidence of ejaculatory disturbances (such as orgasm with little or no fluid) among those taking silodosin.

"Ask about side effects of any Rx."

Koichi Sakata, MD, Department of Urology, Imaichi Hospital, Tochigi, Nikko-shi, Japan, coauthored the study with Tatsuo Morita, MD, Department of Urology, Faculty of Reno-urology Surgery, Jichi Medical University, Tochigi, Shimotsuke-shi, Japan.

The researchers followed 91 men who were diagnosed with BPH with lower urinary tract symptoms. The men, age 55 to 84, were given 4 mg silodosin twice daily from two to 18 months.

Investigators observed ejaculatory disorder in 38 out of 40 patients who were “exercising sexual actions.” The disappearance of semen was noted in 87 percent of those with ejaculation disorder. Of the 38, 29 said they were disturbed by the disorder.

Dr. Morita told dailyRx News, "Silodosin is effective for patients with lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH). Our questionnaire study showed that the administration of silodosin induced ejaculatory disorder at a high incidence in sexually active patients with LUTS by BPH. Since the ejaculatory disorder itself is not harmful for the health but reduces the quality of sexual life, it is necessary to have sufficient information on the ejaculatory disorder before starting the treatment with silodosin."

As a man ages, it is common for the prostate gland to get bigger. BPH rarely causes symptoms before age 40, but more than half of men in their sixties and as many as 90 percent in their seventies and eighties have some symptoms of BPH, according to National Kidney and Urologic Diseases Information Clearinghouse (NKUDIC).

Drugs called alpha blockers are used to treat symptoms. In addition to silodosin, these include terazosin (Hytrin), doxazosin (Cardura), tamsulosin (Flomax) and alfuzosin (Uroxatral).

In a paper published in the October edition of The Canadian Journal of Urology, authors Jack Barkin, MD, Department of Surgery, University of Toronto, and Christine Folia, doctor of pharmacy, Agro Health Associates, Burlington, Ontario, report on the efficacy of silodosin to treat BPH. They also write about promising results the drug has had for ureteral stones and the mixed results it has had for the treatment of prostatitis.

The scientists also commented that family doctors now often prescribe treatment for BPH.

“With the advent of new therapies to treat urological diseases, in many cases, primary management of the patient is often shifted from the urologist to the family physician,” authors wrote.

The study was published in October in BMC Urology from BioMed Central. No conflicts of interest were reported.

Reviewed by: 
Review Date: 
November 5, 2012
Last Updated:
November 11, 2012