A 67-year-old man is evaluated in follow-up for urinary incontinence. Six months ago, he began tamsulosin for occasional nocturia, frequency, and urgency related to benign prostatic hyperplasia. Tamsulosin decreased the frequency of nocturia, but he continued to have daytime urinary urgency with a few occasions of urine leakage. He attempted to control his symptoms with behavioral modification, including bladder training and scheduled voiding, but he still has episodes of urgency and leakage. He prefers not to undergo any surgical intervention. Medical history is otherwise significant for heart failure with preserved ejection fraction. Medications include benazepril, carvedilol, furosemide, spironolactone, tamsulosin, and aspirin.
On physical examination, blood pressure is 102/60 mm Hg, and pulse rate is 72/min. Other vital signs and the remainder of the physical examination are normal.
Bladder ultrasonography shows a postvoid residual urine volume of 30 mL.
Which of the following is the most appropriate treatment?
B. Intermittent bladder catheterization
D. Sacral nerve root neurostimulation
MKSAP Answer and Critique
The correct answer is C. Mirabegron. This content is available to MKSAP 18 subscribers as Question 102 in the General Internal Medicine section. More information about MKSAP is available online.
This patient reports symptoms consistent with urgency urinary incontinence, which can be best addressed with behavioral training and the use of anticholinergic agents or mirabegron. Urgency incontinence is characterized by loss of urine accompanied by a sense of urgency. The treatment of urinary incontinence generally progresses in a stepwise manner. Lifestyle changes and behavioral therapy should be initiated first, followed by pharmacologic therapy and devices, and finally surgery if all other therapies have failed. The patient is already appropriately using behavioral therapy in the form of bladder training and scheduled voiding. The addition of pharmacologic therapy is now appropriate. Anticholinergic drugs (darifenacin, fesoterodine, oxybutynin, solifenacin, tolterodine, trospium) reduce involuntary bladder contractions by blocking the muscarinic cholinergic receptors. Anticholinergic medications are appropriate for both men and women with urgency urinary incontinence, but caution should be exercised when initiating them in men with benign prostatic hyperplasia due to risk for urinary retention. The β-agonist mirabegron, another pharmacologic option for treatment of urgency urinary incontinence, enhances the inhibitory adrenergic signals to the detrusor muscle. Clinicians should base the choice of pharmacologic agents on tolerability, adverse effect profile, ease of use, and cost of medication.
Dutasteride is a 5α-reductase inhibitor used to treat benign prostatic hyperplasia. In this patient who is already being treated with tamsulosin and in whom postvoid residual bladder volume suggests that bladder outlet obstruction has been adequately addressed, there is no additional benefit from adding another therapy for benign prostatic hyperplasia; this therapy will not address the urgency and incontinence problems.
Intermittent self-catheterization might be a useful strategy for a patient with overflow incontinence due to bladder outlet obstruction. However, that is not the case, as demonstrated by this patient's bladder ultrasound, which shows a postvoid residual urine volume of only 30 mL.
Sacral nerve root stimulation is an acceptable treatment for urgency urinary incontinence in patients in whom behavioral and pharmacologic therapies fail. Placement of a sacral nerve root stimulator typically involves conscious sedation and may require general anesthesia.
- Male patients with urgency urinary incontinence who have not achieved satisfactory relief of symptoms with behavioral therapy may benefit from the use of anticholinergic agents or mirabegron.