Finasteride Side Effects: Diarrhea and Chronic Prostatitis

Regarding medications for prostatitis?

Hello, doctor.
I would like to ask about chronic prostatitis.
The doctor prescribed me Finasteride (FINTA) 5mg, and I've been taking it for about a month.
Recently, after taking it for almost two weeks, I've noticed that I often have loose stools.
It's not severe like watery diarrhea, but my stools are looser, resembling symptoms of irritable bowel syndrome.
Before taking the medication, my bowel movements were normal, about once a day, but now I have to go 2-3 times, which is quite bothersome.
I checked the medication leaflet online, and it mentioned diarrhea as a side effect.
Can you tell me if other patients have reported that this medication causes diarrhea and accelerates intestinal motility? If that is the case, how long after stopping the medication should I expect improvement? Thank you.

A-Hong, 30~39 year old female. Ask Date: 2013/11/21

Dr. Xu Weikai reply Urology

Hello, regarding your question, my personal opinion is as follows: Medications affect individuals differently, which creates challenges for physicians when prescribing.
The same medication can produce varying effects and a range of side effects in different patients.
In your case, it seems to be a side effect of the medication, which should improve once the medication is discontinued; typically, it can be completely metabolized within three days.
If you resume the same medication after stopping, there is still a theoretical chance of experiencing the same side effects again.
I recommend discussing with your physician the possibility of changing the prescription to a medication with different active ingredients.
I hope this information is helpful.
If you have further questions, feel free to ask for more discussion and research.
Online responses should only serve as a reference; it is essential to seek medical care at a healthcare facility when necessary.
The Taitung Hospital of the Department of Health, Executive Yuan, cares about you.

Reply Date: 2013/11/21

More Info

Finasteride, commonly known by its brand name Proscar, is a medication primarily used to treat benign prostatic hyperplasia (BPH) and male pattern baldness. While it is generally well-tolerated, it can cause a range of side effects, some of which may be gastrointestinal in nature. Your experience of increased bowel movements and looser stools after starting Finasteride is indeed a recognized side effect, although it may not be the most common one reported.

Diarrhea and changes in bowel habits can occur due to the way Finasteride interacts with the body. The medication works by inhibiting the enzyme 5-alpha-reductase, which plays a crucial role in converting testosterone to dihydrotestosterone (DHT). This hormonal alteration can lead to various systemic effects, including changes in the gastrointestinal tract. Some patients have reported symptoms resembling irritable bowel syndrome (IBS), which can include diarrhea, abdominal pain, and changes in bowel habits.

In your case, the onset of diarrhea after starting Finasteride suggests a possible connection. While not all patients will experience gastrointestinal side effects, they can occur due to individual variations in how the body metabolizes the drug. It is important to note that if these symptoms are bothersome or persistent, it is advisable to consult with your healthcare provider. They may recommend discontinuing the medication or switching to an alternative treatment for your chronic prostatitis.

If you decide to stop taking Finasteride, it typically takes a few days for the drug to be eliminated from your system, and you may start to notice an improvement in your bowel habits within that time frame. However, the exact duration can vary based on individual metabolism and other factors. Generally, most side effects should resolve within a week after discontinuation, but it is essential to monitor your symptoms and communicate with your healthcare provider about any ongoing issues.

In addition to gastrointestinal side effects, Finasteride has been associated with other side effects, including sexual dysfunction (such as decreased libido and erectile dysfunction), breast tenderness, and mood changes. If you are experiencing any of these symptoms, it is crucial to discuss them with your doctor, as they may indicate the need for a change in your treatment plan.

In summary, while diarrhea and changes in bowel habits can occur with Finasteride, it is essential to evaluate the severity of your symptoms and discuss them with your healthcare provider. They can help determine whether the medication is the cause and what steps to take next. Always prioritize open communication with your healthcare team regarding any side effects or concerns you may have about your treatment.

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