Benign prostatic hyperplasia (BPH) is an increasingly important health issue in an aging society. It is a condition in which the prostate gland enlarges and presses on the urethra, causing various urination disorders, with an exceptionally high prevalence in men over the age of 60. According to 2022 data from the Health Insurance Review and Assessment Service, about 81 percent of BPH patients were over 60, highlighting the issue of poor quality of life for older men.

The treatment of BPH is mainly divided into drug therapy and surgical therapy. In the case of drug therapy, drugs such as 5α-reductase inhibitors (5-ARIs) and alpha-blockers are mainly used. Recently, fixed-dose combination drugs (FDCs) that combine these two drugs have been attracting attention as a more effective alternative for patients. Notably, Duodart, approved in Korea in 2021, combines dutasteride and tamsulosin hydrochloride and has gained popularity for its ability to improve adherence and convenience.

Clinical studies have shown that Duodart improves BPH symptoms faster than single-drug therapy, reducing acute urinary retention and the need for surgery. Studies have also shown that early use of combination therapy is beneficial, especially in patients at risk of disease progression, making Duodart an increasingly important treatment option for BPH.

Korea Biomedical Review spoke with Dr. Son Hwan-cheol, a professor of urology at Seoul National University Boramae Medical Center, about the latest trends in BPH treatment and Duodart's clinical performance. Professor Son has more than 20 years of research and clinical experience in urology and has contributed to advances in the diagnosis and treatment of prostate cancer and BPH.

Since taking office as president of the Korean Society for Sexual Medicine and Andrology in 2023, Professor Son has made various efforts to expand academic research and improve patient care in the urology department. As Son wrapped up his two-year term, the urological expert shared his accomplishments and reflections on his work with the academic society.

Question: What is BPH?

Answer: BPH is an enlarged prostate gland that presses on the urethra, causing difficulty urinating, and is most commonly caused by the aging process. The prostate tends to enlarge with age, with a prevalence of about 50 percent in men in their 50s, 60 percent in men in their 60s, and 70 percent in men in their 70s. This means that most men will experience BPH as they age. It is estimated that about one-third of all prostate enlargement patients experience symptoms that make their daily life uncomfortable, and about one-third of them seek medical treatment.

As the average life expectancy in Korea is increasing as the country enters an aging society, the number of patients with BPH is expected to increase. One of the main factors contributing to the acceleration of prostate enlargement is Westernized dietary habits, but it is difficult to prevent prostate enlargement completely through diet alone.

Q: We know that many men with BPH perceive their symptoms as part of aging and delay seeking treatment. But how advanced is their disease, and how is it diagnosed?

A: Most men with BPH visit the clinic at some stage of the disease. Rarely do patients come to us in the very early stages. However, the size of the prostate does not necessarily correlate with the severity of symptoms. Some men experience severe discomfort when their prostate enlarges even slightly, while others experience no discomfort even when their prostate enlarges significantly. In general, symptoms tend to become more severe as the prostate enlarges and as a man ages.

Although BPH is not cancer, it is a condition that causes the prostate to enlarge, so it is very important to differentiate it from prostate cancer. In particular, prostate cancer ranks fourth in the incidence of male cancer in Korea, and its incidence is expected to rise, so more patients need to undergo differential diagnosis. The most important diagnostic tool is the prostate-specific antigen (PSA) test, which can detect and differentiate between various prostate diseases, including BPH and prostate cancer, at an early stage.

In addition, because BPH can be difficult to see on physical examination, a urine velocity test, which measures how quickly urine is expelled during urination, is also used to diagnose the condition. In the past, a rectal hydrops examination was performed to check the size of the prostate, but ultrasound is now commonly used. In addition, patients may be asked to keep a urination diary to analyze the problem, as it may be related to their hydration or dietary habits.

Q: We are also curious about treatment options for BPH. What are the treatment options for BPH?

A: How you choose to manage your BPH is a very important question. In general, treatment starts with non-invasive methods and gradually progresses to more invasive methods if necessary. Most men with BPH who visit a doctor start with medication, and if medication is not sufficiently effective, surgical treatment is a common pathway.

The two main classes of medications used are alpha-blockers and 5α-reductase inhibitors. Alpha-blockers work by relaxing the smooth muscles in the prostate, allowing urine to flow more freely. On the other hand, 5α-reductase inhibitors are drugs that inhibit the growth of the prostate. They work by preventing the conversion of the male hormone testosterone into dihydrotestosterone (DHT). This prostate growth factor reduces the size of the prostate. Dutasteride and finasteride are the most common 5α-reductase inhibitors.

Generally, alpha-blockers are prescribed as the first line of treatment for first-time patients to relax smooth muscle. If the prostate is larger than 30 grams, a 5α-reductase inhibitor may be used in combination to reduce the size of the prostate. Alpha-blockers help relieve symptoms but do not shrink the size of the prostate. However, 5α-reductase inhibitors, such as dutasteride, have been shown to reduce prostate size by about 30 percent in a four-year clinical study. This is a more radical approach, as a 30 p;ercent reduction in prostate size is associated with significant improvement in symptoms.

In terms of surgical treatment, transurethral resection of the prostate (TURP) is the most widely used standard of care. This surgery removes the enlarged prostate gland to relieve pressure on the urethra, allowing urine to flow freely. In recent years, there have been many procedural treatments that can be used before surgical treatment.

The ultimate goal of BPH treatment is to prevent discomfort in patients' daily lives. However, many patients view the condition as a natural part of aging and are willing to live with the discomfort, so treatment decisions are based on subjective patient satisfaction and objective measures such as urinary frequency and residual urine volume.

Q: Recently, fixed-dose combinations (FDCs) that combine two drugs have also been introduced to the market. What are the advantages of combinations over monotherapy?

A: There is a big difference in adherence between taking an alpha-blocker and a 5α-reductase inhibitor and taking Duodart, a combination. Especially as patients get older, the number of medications they need to take increases, and many patients feel uncomfortable with this. With fewer medications, patients are more compliant and respond positively to treatment. Duodart is a combination of dutasteride and tamsulosin hydrochloride, two drugs commonly used to treat BPH. Once patients start taking it, they tend to stick with it.

Q: Since BPH is mainly seen in older men, safety and effectiveness are important factors. How does Duodart compare in terms of safety and side effects?

A: Duodart is a safe treatment that was shown to significantly reduce the risk of acute urinary retention, the need for surgery, and the risk of BPH progression in a four-year, long-term study. Studies found that Duodart was safe and provided stable symptomatic improvement over the long term.

Regarding side effects, the combination of an alpha-blocker and a 5α-reductase inhibitor is not significantly different, meaning that each drug may have its unique side effects. Tamsulosin hydrochloride, an alpha-blocker, was initially developed as a blood pressure medication, so it may have blood pressure-lowering side effects. That’s because it relaxes the prostate smooth muscle and blood vessels together, which can lead to a drop in blood pressure in some patients, as well as retrograde ejaculation. However, given that most men with BPH are in their 50s and 60s, these side effects are less likely to bother them because their semen volume has already decreased due to aging.

5α-reductase inhibitors, such as dutasteride, can cause side effects in terms of sexual function, with sexual dysfunction reported in less than 5 percent of all patients. This has led some patients to avoid 5α-reductase inhibitors for fear of this side effect. Another interesting side effect is hair loss, which is why dutasteride is sometimes used to treat male pattern baldness.

Q: Given the benefits of combination drugs, there will likely be efforts to develop other combinations.

A: In fact, there are as many combinations as there are drugs in use in Korea, but unless it is a widely used drug, such as dutasteride and tamsulosin hydrochloride, there is not much demand. Over the past decade, there have been attempts to develop combinations of other alpha-blockers with erectile dysfunction drugs or overactive bladder drugs, but recent changes in the pharmaceutical landscape have tended to curtail these efforts.

Not only in urology but also in other fields of medicine, drug safety requirements are becoming increasingly stringent, and the cost of developing new drugs is increasing astronomically. Therefore, unless a drug can dramatically outperform the effectiveness of existing treatments, there is little incentive to take the risk and develop a combination drug.

Q: You have served as the president of the Korean Society for Sexual Medicine and Andrology since 2023 and will end your term at year-end. Please tell us about your efforts to advance prostate disease research and solve problems in the field and your plans for the future.

A: The Korean Society for Sexual Medicine and Andrology is a subspecialty society of the Korean Urological Association with more than 40 years of history. Because of its long history and tradition, it is well organized, so, as the president, I didn't have to make many new changes. During my term, I focused on “member interaction” and “research support,” which are the most important aspects of this society.

The society's most significant role is to provide a place for researchers to interact. This is how new ideas can be generated and similar problems solved together. The society also plays a role in taking on research that would be difficult for an individual researcher to conduct. For example, a rare disease that only sees two or three patients yearly in a single hospital can only be studied through a national organization. These studies are conducted at the society level.

Revising guidelines is also an important task. It is difficult to apply guidelines based on overseas situations to Korean patients, so we are working on guidelines that fit the current state of Korean practice. As this society takes on tasks that are difficult for individual researchers, we are also working on disease-specific guidelines at the society level, and the work is now being finalized.

Together with the society's members, I think we have already achieved the goals that I set out when I took office. We recently elected the next president, who will start his term next year, and I am looking forward to the organization's future.

Q: What are your research interests and focuses outside of BPH?

A: Recently, I have been continuing my research on sexual dysfunction through the society. We conducted surveys on sexual dysfunction in men and women in 2004 and 2006, respectively, and this year is the 20th anniversary of the Male Sexual Dysfunction Survey, so we're looking at 20 years of follow-up data. Finalizing the data is one of the most important tasks remaining.

Through our research, we have found that the prevalence of sexual dysfunction in Korea is not significantly different from that in other countries and is quite high. In addition, the treatment environment for female sexual dysfunction in Korea is less accessible than in other countries due to the social culture of tabooing sexuality. These data highlight the need to raise awareness of sexual dysfunction and expand access to treatment.

Q: Do you have any messages for patients with BPH?

A: Although talking about urological conditions is much more natural than in the past, many patients are still reluctant to visit a doctor. Prostate enlargement is a common condition that can affect anyone, so please don't feel any unnecessary pressure to visit a doctor. If you're over 50 and you're having trouble urinating, you should consider the possibility of prostate disease. If you're experiencing any discomfort with urination, it's important to be proactive and seek medical attention.