Side Effects of Prostate Medicines: What Men Should Know
Prostate medicines can improve weak urine flow, straining, frequent urination, night-time urination and incomplete bladder emptying. But they can also cause side effects such as dizziness, low blood pressure, tiredness, blocked nose, dry ejaculation, reduced sexual desire, erection difficulty, breast tenderness, dry mouth or constipation. Most side effects are manageable, but some need urgent attention. Do not stop or change prostate tablets on your own. A urologist can adjust the dose, timing or medicine type, and can check whether the bladder is emptying safely.
Short answer: are side effects of prostate medicines common?
Yes, side effects can happen, but they depend on the type of prostate medicine. Some prostate medicines mainly affect blood pressure and ejaculation. Some affect sexual desire, erection quality or semen volume. Some bladder medicines used along with prostate treatment can cause dry mouth, constipation or difficulty passing urine.
The important thing is not to silently tolerate side effects or stop tablets suddenly. Many problems can be solved by changing the timing, switching the medicine, reviewing BP or heart medicines, or checking urine flow and post-void residual urine.
Common prostate medicines and possible side effects
Drug choice should depend on symptoms, prostate size, post-void residual urine, BP medicines, sexual priorities and other medical problems. NICE recommends considering existing medicines, medical conditions and symptom severity before starting drug treatment for male lower urinary tract symptoms.
| Medicine type | Common examples | Common side effects |
|---|---|---|
| Alpha blockers | Tamsulosin, silodosin, alfuzosin, doxazosin, terazosin | Dizziness, low BP, tiredness, blocked nose, ejaculation changes |
| 5-alpha reductase inhibitors | Finasteride, dutasteride | Reduced libido, erection difficulty, reduced semen, breast tenderness, lower PSA |
| PDE5 inhibitor | Tadalafil | Headache, acidity, flushing, back pain, BP drop with certain medicines |
| Antimuscarinic bladder medicines | Solifenacin, tolterodine, oxybutynin, fesoterodine | Dry mouth, constipation, blurred vision, difficulty passing urine |
| Beta-3 agonist | Mirabegron | Raised BP, headache, UTI-like symptoms, urinary retention in selected men |
| Desmopressin | Selected cases of night-time urine overproduction | Low sodium, headache, nausea, weakness or confusion |
Side effects of alpha blockers
Alpha blockers are commonly used for enlarged prostate symptoms. They relax the prostate and bladder neck muscle, so urine flow can improve within days. Common examples include tamsulosin, silodosin, alfuzosin, doxazosin and terazosin.
Dizziness and low blood pressure
Dizziness is one of the most important side effects. It may happen when standing up suddenly, walking to the toilet at night or taking BP medicines along with prostate tablets.
EAU guidelines list weakness, dizziness and orthostatic hypotension as frequent alpha-blocker side effects. Men with cardiovascular disease or vasoactive medicines may be more susceptible. This matters especially in elderly patients, diabetic patients, patients on multiple BP medicines and men who wake up at night to urinate.
Ejaculation changes
Tamsulosin and silodosin can cause reduced semen, absent semen or dry ejaculation. This is usually not dangerous, but it can be distressing if not explained beforehand.
This does not usually mean loss of orgasm. But men trying for pregnancy should discuss this before starting or continuing treatment.
Blocked nose, fatigue and headache
Some men feel nasal stuffiness, tiredness, mild headache or general weakness. These may settle after a few days, but persistent symptoms should be discussed.
Cataract surgery warning
Tell your eye surgeon if you are taking or have previously taken tamsulosin, silodosin, alfuzosin, doxazosin or terazosin. Alpha blockers can be associated with intraoperative floppy iris syndrome, a problem that can affect cataract surgery. Do not stop the medicine on your own, but make sure the ophthalmologist knows.
Side effects of finasteride and dutasteride
Finasteride and dutasteride are 5-alpha reductase inhibitors. They reduce the hormone effect that contributes to prostate enlargement. They are usually considered when the prostate is significantly enlarged or when the risk of urinary retention or future surgery needs to be reduced.
These medicines work slowly. They usually take months to show full benefit, so some patients are given an alpha blocker initially for faster symptom relief.
Reduced libido, erection difficulty and semen changes
The main side effects are sexual. Men may notice reduced desire, erection difficulty or reduced semen volume. Not every patient gets these side effects, but they should be discussed openly, especially in younger men, sexually active men and men already worried about erection quality.
Breast tenderness or swelling
Finasteride and dutasteride can rarely cause breast tenderness, nipple sensitivity or breast enlargement. A breast lump, nipple discharge, one-sided swelling or persistent pain should be checked.
PSA level becomes lower
Finasteride and dutasteride can lower PSA after several months. This means PSA reports must be interpreted differently in men taking these medicines. Always tell your urologist if you are taking finasteride or dutasteride before discussing a PSA report.
Mood symptoms
Some studies and regulatory warnings have discussed possible mood-related symptoms with 5-alpha reductase inhibitors. If you notice new low mood, anxiety, lack of motivation or disturbing thoughts after starting treatment, speak to your doctor promptly.
Side effects of tadalafil for prostate symptoms
Tadalafil may be used in selected men with urinary symptoms, especially when erectile dysfunction is also present. It is not suitable for everyone.
Common side effects include headache, flushing, acidity, indigestion, back pain, muscle pain and blocked nose. The major safety warning is drug interaction.
Important tadalafil safety warning
Do not take tadalafil with nitrate medicines used for chest pain or heart disease. This combination can cause a dangerous fall in blood pressure. Tadalafil can also lower BP when combined with some alpha blockers, BP medicines or alcohol.
Tell your doctor if you take medicines for BP, chest pain, heart disease, pulmonary hypertension, erectile dysfunction or recreational “performance” tablets.
Side effects of bladder medicines used with prostate treatment
Some men with prostate enlargement also have urgency, frequent urination, urge leakage or night-time urination. These are storage symptoms. Bladder medicines may help, but they should be used carefully if bladder emptying is poor.
Antimuscarinic medicines
Examples include solifenacin, tolterodine, oxybutynin and fesoterodine. Common side effects include dry mouth, constipation, blurred vision, dizziness and sleepiness. In some men, they may worsen incomplete bladder emptying.
These medicines should not be self-started in men with poor urine flow, high post-void residual urine or previous urinary retention.
Mirabegron
Mirabegron may help urgency and frequency, often with less dry mouth than antimuscarinic tablets. But it can raise BP in some patients and is usually avoided in severe uncontrolled hypertension. BP should be checked before and during treatment.
Desmopressin for night-time urination
Desmopressin is not a routine prostate tablet. It may be used in selected patients whose main problem is excess urine production at night. The main safety issue is low sodium, especially in older patients. Weakness, nausea, confusion or worsening drowsiness after starting desmopressin should be taken seriously.
Which side effect may belong to which tablet?
| Side effect | Possible medicine link | What to do |
|---|---|---|
| Dizziness or faint feeling | Alpha blockers, tadalafil combinations | Check BP, avoid driving if dizzy, consult doctor |
| Dry ejaculation or reduced semen | Tamsulosin, silodosin; sometimes finasteride/dutasteride | Discuss if fertility or sexual satisfaction matters |
| Reduced sexual desire or erection difficulty | Finasteride, dutasteride | Review medicines and other causes like diabetes, BP, sleep and hormones |
| Dry mouth and constipation | Antimuscarinic bladder medicines | Do not ignore severe constipation or worsening urine flow |
| Raised BP | Mirabegron | BP monitoring is important |
| Confusion, severe weakness or nausea | Desmopressin-related low sodium risk | Seek medical care promptly |
Which side effects need urgent attention?
Seek urgent medical care if you have:
- Complete inability to pass urine
- Fever with burning urination or chills
- Severe lower abdominal pain with bladder fullness
- Fainting or repeated falls
- Chest pain after taking tadalafil
- Painful erection lasting more than four hours
- Sudden vision or hearing loss after tadalafil
- Blood in urine with clots
- Severe weakness, confusion or vomiting after starting desmopressin
- Severe allergic reaction, swelling or breathing difficulty
When should you call your urologist but not panic?
Book a urology review if you notice:
- Dizziness after starting prostate tablets
- Dry ejaculation or reduced semen
- Reduced sexual desire
- New erection difficulty
- Breast tenderness or swelling
- Constipation after bladder medicines
- Worsening difficulty passing urine after urgency tablets
- No improvement despite regular medicine use
- Confusion about PSA while taking finasteride or dutasteride
- Cataract surgery planned while taking alpha blockers
Should you stop prostate medicines if side effects occur?
Do not stop or change prostate medicines on your own unless you have a severe reaction and urgent medical care is needed.
Stopping tablets suddenly may bring back weak flow, straining, frequent urination or urinary retention risk. A urologist may instead change the timing, switch the medicine, reduce unnecessary combinations, check sitting and standing BP, review heart and BP medicines, measure post-void residual urine, or discuss surgery if tablets are not suitable.
When medicines may not be enough
Medicines may not be enough if you have repeated urinary retention, recurrent urine infections, bladder stones, kidney swelling, worsening kidney function, repeated bleeding due to prostate enlargement or severe symptoms despite tablets.
In such cases, a urologist may discuss procedures such as TURP, bipolar TURP, HoLEP, laser prostate surgery or other BPH procedures depending on prostate size, bladder function, anaesthesia fitness and patient priorities.
If you are taking prostate tablets and noticing dizziness, dry ejaculation, sexual side effects, poor improvement, worsening urgency or difficulty passing urine, a urology review can help.
Consultation checklist: what to bring
- Current prostate medicine strips or prescriptions
- BP, diabetes, heart and blood thinner medicine list
- Urine routine report
- Urine culture report, if done
- Ultrasound KUB/prostate size/post-void residual report
- PSA report, if done
- Serum creatinine report
- Uroflowmetry report, if done
- Catheter or discharge summary, if any
- Eye surgery/cataract surgery history
- A note of your exact side effect and when it started
Also tell your doctor if sexual function, fertility, ejaculation, dizziness while driving or cataract surgery is a major concern.
FAQs
Are side effects of prostate medicines permanent?
Most side effects improve after dose adjustment, medicine change or stopping the medicine under medical guidance. Persistent sexual or mood symptoms have been reported by some men after 5-alpha reductase inhibitors, but this remains an area of ongoing research.
Which prostate medicine causes dry ejaculation?
Tamsulosin and silodosin commonly cause reduced semen or dry ejaculation. It is usually not dangerous, but it should be discussed if fertility or sexual satisfaction is important.
Can prostate medicines cause erectile dysfunction?
Finasteride and dutasteride can cause erection difficulty in some men. Alpha blockers more commonly affect ejaculation than erection. Tadalafil may improve erections in suitable patients.
Can prostate tablets affect PSA?
Yes. Finasteride and dutasteride can lower PSA significantly after months of treatment. Always tell your doctor if you are taking these medicines before PSA interpretation.
Can I take tadalafil with tamsulosin?
This should be decided by a doctor. Tadalafil can lower BP when combined with alpha blockers, BP medicines or alcohol, and it must not be taken with nitrates.
What should I do if prostate medicine causes dizziness?
Avoid sudden standing, dehydration and alcohol excess. Do not drive if dizzy. Contact your doctor because the dose, timing or medicine may need adjustment.
Can bladder tablets worsen urine blockage?
Yes, in some men with poor bladder emptying. That is why post-void residual urine may need to be checked before or after starting urgency medicines.
Should I tell my eye doctor about prostate tablets?
Yes. Tell your eye surgeon if you take or previously took alpha blockers, especially before cataract surgery.
Related reading
- Enlarged Prostate: Symptoms, Causes and Treatment
- Prostate Medicines Explained
- Alpha Blockers for Prostate Enlargement
- Finasteride and Dutasteride for Prostate Enlargement
- Can Prostate Medicines Affect Sexual Function?
- Prostate Size on Ultrasound: Does Size Matter?
- Sudden Inability to Pass Urine
- TURP Surgery for Prostate Enlargement
- Enlarged Prostate / BPH Treatment
- Urologist in Latur
References
- European Association of Urology. EAU Guidelines on the Management of Non-neurogenic Male LUTS, 2026 https://uroweb.org/guidelines/management-of-non-neurogenic-male-luts
- NICE. Lower urinary tract symptoms in men: management https://www.nice.org.uk/guidance/cg97/chapter/Recommendations
- Urology Care Foundation. Benign Prostatic Hyperplasia patient information https://www.urologyhealth.org/urology-a-z/b/benign-prostatic-hyperplasia-bph
- American Urological Association. Benign Prostatic Hyperplasia (BPH) Guideline, 2026 https://www.auanet.org/guidelines-and-quality/guidelines/benign-prostatic-hyperplasia-bph-guideline
- FDA. Cialis/tadalafil prescribing information https://www.accessdata.fda.gov/drugsatfda_docs/label/2011/021368s20s21lbl.pdf
- Trost L, Saitz TR, Hellstrom WJG. Side Effects of 5-Alpha Reductase Inhibitors. Sexual Medicine Reviews https://pubmed.ncbi.nlm.nih.gov/27784557/
- Halawani A, et al. Risks and side effects in the medical management of benign prostatic hyperplasia https://pmc.ncbi.nlm.nih.gov/articles/PMC11255900/