Medical treatment of Stress Urinary Incontinence
Introduction
Stress urinary incontinence (SUI) is one of the most common and distressing lower urinary tract disorders in both women and men. It affects quality of life, mental health, and social function. While surgery remains the mainstay of treatment, drug therapy continues to attract interest as a non-invasive option. Understanding current pharmacological strategies is essential for safe, evidence-based practice.
Important concepts
- Stress urinary incontinence (SUI): Involuntary urine leakage during activities that increase intra-abdominal pressure such as coughing, sneezing, or exertion.
- α-adrenoceptors: Receptors present in the urethra that mediate smooth muscle contraction and increase urethral closure pressure.
- Onuf’s nucleus: A spinal cord nucleus that controls the external urethral sphincter via serotonergic and noradrenergic pathways.
- Serotonin-norepinephrine reuptake inhibitors: Drugs that increase central neurotransmitters affecting urethral sphincter tone.
- Leak point pressure: The bladder pressure at which urine leakage occurs without detrusor contraction.
- Myostatin pathway: A biological pathway that inhibits muscle growth and affects pelvic floor strength.
What we know
α-adrenoceptors
- α-adrenoceptors are present in high density in the urethra, especially α1A subtype.
- Stimulation of these receptors increases smooth muscle contraction in the urethra.
- α-agonists show better results in symptom improvement rather than complete cure.
- Systemic receptor distribution limits their safety profile.
- Local delivery strategies show more favorable outcomes.
Deluxetine
- Duloxetine increases urethral tone through central serotonergic and noradrenergic pathways.
- Central nervous system modulation plays a key role in continence mechanisms.
- Urethral pressure improves with serotonin and norepinephrine activity.
- Antidepressant therapy shows physiological effects but limited tolerability.
- Adverse effects restrict long-term clinical use.
Local estrogen therapy
- Local estrogen therapy improves subjective symptoms in postmenopausal women.
- Selective androgen receptor modulation improves pelvic floor muscle function.
- Experimental drugs target muscle growth and sphincter strength.
- New pharmacological targets aim for tissue-specific action.
Important numbers
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54.33% vs 38%
Median pad weight reduction with PSD-503 (local α-agonist therapy) vs placebo. This suggests better symptom control with local α-agonist therapy. -
Odds Ratio (OR) 1.22 (95% CI 0.47–3.03)
Cure rates using α-agonists.
Indicates weak evidence for complete cure. -
OR 2.28 (95% CI 1.60–3.30)
Symptom improvement with α-agonists.
Shows benefit for symptom relief rather than cure. -
6.5 cmH₂O & 7.9 cmH₂O
Increase in urethral pressure with imipramine.
Physiological effect without clinical significance. -
15%
Side effects in post-prostatectomy duloxetine group.
Includes nausea, fatigue, light-headedness, dry mouth. -
22.1%
Adverse events in 6,395 duloxetine-treated patients.
High discontinuation risk due to side effects. -
UDI-6: 83.3 → 33.3
Estriol therapy symptom score improvement.
Indicates strong subjective improvement. -
57.5% vs 47.35%
SUI episode reduction with TAS-303 (an experimental selective inhibitor of norepinephrines) vs placebo.
Shows modest but statistically significant benefit.
The Urologist’s Summary
-
Clinical symptom assessment
Identify leakage during coughing, exertion, sneezing, or physical activity. -
Risk factor evaluation
Assess history of childbirth, pelvic surgery, menopause, obesity, and prostatectomy. -
Functional assessment
Use symptom scores, pad tests, and patient-reported outcome measures where available. These list of medications are potential theraputics for SUI that neede further investigations: alpha agonists, duloxetine, SSRI, and local estrogen therapy.
The point
Drug therapy in SUI shows limited efficacy compared to surgery, and future pharmacological strategies must focus on targeted action with fewer systemic side effects.
For further data about urologic diseases diagnosis and therapeutic options, follow our blog
The Urologist
By:
Dr. Ahmed M. Bakr, MD, FEBU
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