Which medication can assist in decreasing urethral resistance in cases of overflow incontinence due to BPH?

Tamsulosin is a selective alpha-1 adrenergic antagonist that is commonly used to manage symptoms associated with benign prostatic hyperplasia (BPH). By blocking alpha-1 receptors in the smooth muscle of the prostate and bladder neck, tamsulosin effectively reduces urethral resistance. This mechanism alleviates difficulty in urination and helps decrease urinary retention that can occur with overflow incontinence related to BPH.

Overflow incontinence happens when the bladder cannot effectively empty, leading to an involuntary leakage of urine. In patients with BPH, an enlarged prostate can obstruct the urethra, causing an increase in urethral resistance. By relaxing the smooth muscle in the prostate and bladder neck, tamsulosin allows for improved urine flow and reduced urinary retention, thereby addressing the overflow incontinence.

Other medications listed have different mechanisms and may not specifically target urethral resistance in the same manner. Mirabegron primarily acts as a beta-3 adrenergic agonist, promoting bladder relaxation but not directly affecting urethral resistance. Oxybutynin is an anticholinergic that reduces bladder spasms but does not specifically relieve obstruction caused by BPH. Bethanechol, a cholinergic agent,