This patient’s presentation is consistent with benign prostatic hyperplasia (BPH). Preferred medical treatment of BPH includes an alpha-1 adrenergic blocker (ex. tamsulosin) and/or a 5-alpha reductase inhibitor (ex. finasteride).
The prostate gland is located distal to the outflow tract of the bladder. Therefore, enlargement or hyperplasia of the prostate, especially in the periurethral transitional zone, presents with increased urinary hesitancy and frequency. 5-alpha reductase inhibitors act by inhibiting the conversion of testosterone to dihydrotestosterone, an important mediator of prostatic growth.
Edwards describes the management of BPH. The report states that for men with mild symptoms, watchful waiting with annual reassessment is most appropriate. If needed, alpha-blockers improve symptoms relatively quickly. Comparatively, 5-alpha reductase inhibitors have a slower onset of action but may in fact alter the disease course. Transurethral resection of the prostate (TURP) often provides permanent relief but has associated surgical complications including incontinence.
Cohen et al. review the efficacy of combination pharmacological treatment of BPH. Thy note that clinical trials of medical therapy for BPH have confirmed the finding that combined therapy with an a(1)-adrenergic receptor (AR) antagonist and a 5a-reductase inhibitor is superior to either agent alone.
Image A is a transabdominal ultrasound demonstrating enlargement of the prostate gland as seen in BPH. Illustration A shows the progression and consequences of BPH. Illustration B is an axial CT of BPH. Notice the prostate sits posterior to the pubic symphysis and anterior to the anal canal.
Answer 1: Clonidine is an alpha-2 adrenergic agonist, which would have the undesired effect of increasing urethral resistance to flow; this agent can be used to treat stress urinary incontinence. Clonidine also has anticholinergic effects, which is a contraindication in the setting of BPH.
Answer 3: This would not improve BPH symptoms; in fact, it might have the opposite effect. Recall that finasteride, which prevents conversion of testosterone to dihydrotestosterone is effective in the setting of BPH.
Answer 4: Antihistamines should be avoided in patients with BPH.
Answer 5: As a diuretic, furosemide can worsen symptoms of BPH.
Edwards JL. Diagnosis and management of benign prostatic hyperplasia. Am Fam Physician. 2008 May 15;77(10):1403-10.
PMID:18533373 (Link to Abstract)
Cohen SA, Parsons JK. Combination pharmacological therapies for the management of benign prostatic hyperplasia. Drugs Aging. 2012 Apr 1;29(4):275-84.
PMID:22428659 (Link to Abstract)
USMLE World Step 1 QBank Question #1737. Copyright © USMLEWorld, LLC 2012