Silodosin, a prescription medicine used to treat an enlarged prostate, can prolong the length of time it takes to ejaculate, a study conducted by Stephen Yang (楊緒棣), surgeon-in-chief at Buddhist Tzu Chi General Hospital’s Taipei Branch, has suggested.
The study involved 26 sexually active patients who had taken Silodosin for the treatment of benign prostatic hyperplasia over the period of six-and-a-half months.
The results showed that average intravaginal ejaculation latency time (IELT), which means the time between the start of vaginal intromission and the start of intravaginal ejaculation, in men who took the drug increased from four minutes to 5 minutes, 48 seconds, with seven men saying their IELT was greatly extended, while eight men said they felt no significant difference.
The average age of the patients was 56 years old.
In Taiwan, one in every two men aged 50 or older has an enlarged prostate, Yang said.
Silodosin is also said to work for younger men.
In one study conducted in Japan, eight men in their 30s who suffered from premature ejaculation reported that their average IELT increased from three minutes to 10 minutes, with six saying the improvement was “significant,” Yang said.
Yang’s study also suggests the drug works better for those who suffer from premature ejaculation, extending their IELT from 1 minute, 30 seconds to three minutes.
The average time for those without the problem increases from five minutes to 6 minutes, 48 seconds, he said.
Yang said it is clinically understood that a premature ejaculation happens less than two minutes after penetration, while the IELT needs to be three minutes or longer for women to “feel satisfied.”
The physician said he was interested in looking into the effects of the drug after hearing the reactions of patients who had taken it.
“One day, a woman came in with her 65-year-old husband and asked what kind of medicine I had prescribed him because it made him able to have sex for 30 minutes. Soon the same thing happened with another patient who was 63 years old. Then I knew something was not right,” said Yang, who is also a professor of urology at Tzu Chi University in Hualien City.
Having been developed and received its first marketing approval in Japan in 2006, Silodosin has been available in Taiwan since last year.
Another interesting finding, Yang said, is that the drug provides evidence that the male orgasm is not necessarily connected with the occurrence of ejaculation.
As Silodosin has the ability to block seminal vesicles from secreting and thus preventing the release of semen, half of the patients in the study had no ejaculation, while 47 percent had a decreased sperm count.
However, 97 percent of the subjects reported having an orgasm.
Citing studies conducted in Japan, Yang said Silodosin is completely effective in inhibiting ejaculation as no sperm is detected in the samples provided by volunteers in the studies.
“The drug has the potential to be used as a means of male birth control, but we also need to understand that younger men have a different perception of sex than older men,” the researcher said.
“To them, it is psychologically important to have an ejaculation,” he said.
Both medical studies and clinical experience show that the effect of inhibiting ejaculation is reversible.
Patients can resume the normal ejaculatory function after they stop taking Silodosin for two to three days, Yang said.
Yang and his team are planning to undertake a large-scale research project on Silodosin and expect to publish the results in March next year.
“This particular medicine is very unique, and it has been generating more and more interest,” Yang said.
“I believe we will find out more about its applications in the next few years,” he added.