From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Tamsulosin does not typically affect PSA levels, so routine PSA monitoring can continue on the same schedule as before starting the medication. For men undergoing regular PSA screening, this usually means annual testing. There is no need to obtain a special follow-up PSA test after initiating tamsulosin therapy. This differs from 5-alpha reductase inhibitors like finasteride or dutasteride, which can lower PSA levels by approximately 50% after 6-12 months of treatment. Tamsulosin is an alpha-1 adrenergic receptor blocker that relaxes smooth muscle in the prostate and bladder neck to improve urinary symptoms, but it does not alter prostate size or PSA production. Therefore, any significant change in PSA while on tamsulosin should be evaluated as it would be in any patient, as it could potentially indicate prostate pathology rather than a medication effect. Patients should be reminded that PSA testing remains an important part of prostate cancer screening even while taking tamsulosin for benign prostatic hyperplasia.
Some studies have investigated the effects of tamsulosin on PSA levels, such as the study by 1, which found that tamsulosin can reduce PSA levels in patients with lower urinary tract symptoms and an elevated PSA level. However, this effect is not significant enough to alter the routine PSA monitoring schedule.
It's also worth noting that other factors, such as digital rectal examination and prostatic massage, can affect PSA levels, as shown in the study by 2. However, these effects are generally minimal and do not impact the routine PSA monitoring schedule.
In terms of the frequency of PSA testing, the study by 3 highlights the importance of combining PSA testing with digital rectal examination for early detection of prostate cancer. However, this does not change the fact that tamsulosin does not typically affect PSA levels, and routine PSA monitoring can continue as usual.
Overall, the evidence suggests that tamsulosin does not significantly affect PSA levels, and routine PSA monitoring can continue on the same schedule as before starting the medication.