Mirabergon added to tamsulosin improves frequent urination and overactive bladder symptoms among patients with prostate cancer who received brachytherapy. However, the combination did not improve voided volume per micturition, according to study findings.

Yasushi Nakai, MD, Department of Urology, Nara Medical University, Nara, Japan and colleagues conducted an open-label, randomized, non–placebo-controlled trial to examine the effect of adding mirabegron to tamsulosin among patients who received ¹²⁵I-brachytherapy for prostate cancer.

The trial enrolled 218 patients who underwent ¹²⁵I-bradcytherapy for prostate cancer in a single institution between September 2016 and October 2018. Patients were randomized in a 1:1 ratio to receive tamsulosin plus mirabegron (n = 108) or tamsulosin alone (n = 110) after ¹²⁵I-bradcytherapy.

The primary end point of the study was the change in mean voided volume per micturition 3 months after ¹²⁵I-bradcytherapy. Secondary end points included changes in International Prostate Symptom Score, Overactive Bladder Symptom Score, and Expanded Prostate Cancer Index Composite scores and 24-hour urinary frequency.

The mean changes in volume voided per micturition was -62.5 in the mirabegron group and -68 in the tamsulosin alone group (P = .17). The change in Overactive Bladder Symptom score was more moderate in the mirabegron group vs the tamsulosin group (P = .02). In addition, 24-hour urinary frequency was lower in the mirabegron group than the tamsulosin alone group (P = .03). Retention rates within 3 months of ¹²⁵I-bradcytherapy were 7.3% and 6%, respectively (P = .8).

“Tamsulosin and mirabegron combination therapy after ¹²⁵I-brachytherapy did not improve voided volume per micturition compared to tamsulosin-only treatment. However, it could improve frequent urination and overactive bladder symptoms,” Dr Nakai and colleagues concluded.

Source:

Nakai Y, Tanaka N, Asakawa I, et al. Mirabegron Reduces Urinary Frequency and Improves Overactive Bladder Symptoms at 3 Months After 125I-brachytherapy for Prostate Cancer: An Open-Labeled, Randomized, Non–Placebo-Controlled Study. Urology. 2022;161:87-92. doi:10.1016/j.urology.2021.12.018.