Urinary Incontinence in Adults

Urinary incontinence (UI) is the complaint of involuntary leakage of urine — a symptom, not a single diagnosis.^[1] The four principal mechanisms are stress incontinence (urethral sphincter incompetence overwhelmed by increased intra-abdominal pressure), urgency incontinence (detrusor overactivity, usually as part of overactive bladder syndrome), overflow incontinence (chronic urinary retention from a noncontractile bladder or bladder outlet obstruction, with dribbling and leakage from an overdistended bladder), and functional incontinence (a normal lower urinary tract, but leakage from an inability to reach or use the toilet in time because of mobility, cognitive, or environmental barriers). Mixed incontinence combines stress and urgency features. Correctly identifying which mechanism (or combination) is driving a given patient's leakage is the single most important step in management, because the treatments are not interchangeable — an antimuscarinic that helps urgency incontinence can actively worsen overflow incontinence, and pelvic floor muscle training that is first-line for stress incontinence does little for urgency incontinence. Never start empiric drug therapy for incontinence without first establishing which type is present.

Urinary incontinence is diagnosed by taking a focused history — no single physical finding or lab test "makes" the diagnosis. A validated screening tool such as the 3-question incontinence questionnaire (3IQ) efficiently distinguishes stress-predominant, urgency-predominant, and mixed incontinence in a primary care or pharmacy setting: (1) has the patient leaked urine in the last 3 months; (2) did leakage occur with physical activity, with urgency, with neither, or with both about equally; (3) which pattern occurs most often.^[1] The presentation of each type is distinct enough to guide an initial working diagnosis before any testing is done.

• Caffeine intake.
• Fluid intake — both inadequate and excessive matter; a total daily intake of roughly 1.5-2 L/day is generally appropriate.
• Limited physical activity.
• Restricted mobility or environmental challenges, including dexterity in removing clothing and accessibility of toilets.
• Smoking.
• Benign prostatic hyperplasia.
• Bowel problems — constipation or fecal impaction.
• Poorly controlled diabetes mellitus.
• Lower urinary tract conditions — urinary tract infection, urogenital atrophy.
• Obesity, particularly abdominal obesity.
• Obstructive sleep apnea.
• Cognitive impairment or delirium (contributes to functional incontinence specifically).
• Prior pelvic surgery, pelvic radiation, or an obstetric injury (particularly with forceps use, a prolonged second stage, or delivery of a larger infant) — risk factors for stress incontinence via sphincter or pelvic floor injury.

Medications that can cause or worsen incontinence

A focused medication review is one of the highest-yield steps in assessing any patient with new or worsening incontinence — reversing a contributing drug is often more effective, and always safer, than starting a new one.

Differentiating the mechanisms of incontinence

Mixed incontinence combines stress and urgency features and is managed by treating the predominant (more bothersome) symptom.

History

• Characterize the leakage: onset, frequency, severity, triggers, and volume; use a validated tool such as the 3IQ to help classify stress-predominant, urgency-predominant, or mixed patterns.
• Degree of bother and impact on daily function and emotional well-being — this shapes how aggressively to treat, not just whether incontinence is present.
• Previous treatments tried (pelvic floor therapy, pessary, surgery, containment products) and the current number of pads/products used per day.
• A 3-day bladder diary (fluid intake, voiding frequency, timing, volume, and leakage episodes) is useful for decision-making; longer diaries add patient burden without meaningfully more information.
• Obstetric history (vaginal versus Cesarean delivery, forceps use), menopausal status, and bowel habits (constipation is both a risk factor and a modifiable contributor).
• Medical history for conditions associated with incontinence: diabetes, depression, mobility or cognitive impairment, prior bladder or pelvic surgery, and neurologic conditions (multiple sclerosis, stroke, spinal cord injury).
• Full medication history, including nonprescription products and natural health products, and any recent medication changes — see Risk Factors for the specific drug classes to review.

Physical examination

• Neurologic exam — mental status/cognition, and evidence of central or peripheral neurologic disease.
• Pelvic examination — assess pelvic floor tone, rule out a pelvic mass or organ prolapse, and check for latent stress incontinence and urogenital atrophy.
• Rectal examination — tone, masses, and fecal impaction.
• Functional assessment — dexterity, mobility, and vision, since impairment in any of these can drive functional incontinence independent of the lower urinary tract.

Investigations

• Cough test — immediate leakage on coughing suggests stress incontinence; delayed leakage suggests urgency incontinence.
• Urinalysis — to rule out infection, glucosuria, or hematuria.
• Post-void residual (PVR) — under 50 mL is normal; consider intervention (further workup, catheterization) once PVR reaches roughly 100-150 mL or more.
• Renal function testing (urea, creatinine, glucose, calcium) when renal dysfunction is suspected or polyuria is present.
• Urodynamic testing — accessed through specialist referral (urology, geriatrics) to measure detrusor compliance and contractility, PVR, and bladder capacity; not needed for straightforward, typical presentations.

• Relieve urinary symptoms and reduce leakage episodes.
• Prevent complications — skin breakdown, falls (particularly from nocturia and rushing to the toilet in older adults), recurrent urinary tract infection, and social withdrawal or low mood related to incontinence.
• Improve quality of life and restore confidence in daily activities.
• Correctly identify and treat the type-specific mechanism driving leakage, rather than pursuing generic symptomatic control.
• Avoid treatment-related harm — particularly anticholinergic burden in older adults and inadvertent worsening of overflow incontinence.
• Improve bladder function and, where relevant, restore functional continence by addressing mobility, cognitive, or environmental barriers.

Stress incontinence

• Pelvic floor muscle exercise (PFME) — a self-guided program of 12-20 muscle contractions, 3-5 times per day, holding each contraction toward a goal of 10 seconds; benefit may take 6-8 weeks to appear.
• Pelvic floor muscle training (PFMT), also called pelvic floor physical therapy — a professional-led version of the same principle, delivered by a physiotherapist specializing in pelvic floor disorders; in males, evidence-based guidelines recommend PFME/PFMT before prostate resection and in the immediate postoperative period.
• Biofeedback and/or electrical stimulation therapy to help the patient isolate and control the pelvic floor muscles.
• Weight loss in patients who are overweight or obese.
• Vaginal devices — a pessary for patients with vaginal prolapse; single-use tampon-like inserts; weighted vaginal cones (less evidence, but a reasonable option with results similar to PFME).
• Surgical options depend on etiology: a midurethral mesh sling (retropubic or transobturator; single-incision slings are a less-effective variant) is the most common intervention in females and may also be used in males after prostatectomy once non-invasive options have been tried; periurethral bulking agents (e.g., collagen or synthetic gel) are less effective, with benefit that can decline substantially within 6 months; retropubic suspension is a last-line surgical option.^[2]

Urgency incontinence / overactive bladder

• Bladder training (timed voiding) — a voiding schedule gradually lengthened toward a reasonable interval with minimal incontinence, for example starting at 1-hour intervals and increasing weekly toward voiding every 2-3 hours; more effective than antimuscarinic therapy in comparative studies and should be tried first.
• Pelvic floor muscle exercise, using the same technique described for stress incontinence.
• Weight loss in overweight or obese patients — reduces nocturia, urgency, and stress incontinence, though sustaining weight loss long-term is a genuine challenge.
• Smoking cessation.
• Caffeine reduction (not necessarily complete cessation).
• Moderate fluid intake — a modest reduction in daytime fluid can reduce daytime frequency, urgency, and nocturia in some patients, but avoid aggressive fluid restriction, since concentrated urine can itself irritate the bladder and worsen constipation.
• Biofeedback training and electrical stimulation, including protocols using tibial neurostimulation.
• Sacral or tibial neuromodulation is an accepted 3rd-line option for refractory urgency incontinence, alongside onabotulinumtoxinA.^[3]

Overflow incontinence

• Address the underlying cause directly: stop or substitute medications that impair bladder emptying (anticholinergics, calcium channel blockers, sympathomimetics/decongestants, opioids).
• Catheterization (intermittent, indwelling, or suprapubic) for chronic retention due to detrusor underactivity — intermittent catheterization is generally preferred when feasible.
• For overflow incontinence from bladder outlet obstruction (e.g., benign prostatic hyperplasia), manage the obstruction directly — medical or surgical therapy as appropriate; see Lower Urinary Tract Symptoms and Benign Prostatic Hyperplasia for detailed management of BPH itself.

Functional incontinence

• Scheduled or prompted toileting at regular intervals.
• Improve toilet access — proximity, lighting, grab bars, raised toilet seats, and clothing that is easy to remove quickly.
• Address the underlying mobility, cognitive, or mood disorder driving the functional barrier wherever possible.
• Containment products designed specifically for incontinence (not menstrual products) — correct absorbency, placement of the absorbent core, and odour control differ from menstrual products, and using the wrong type of product for the patient's anatomy or type of incontinence undermines management.

General counselling, all types

• Set realistic expectations: nonpharmacologic interventions generally need 6-12 weeks to show benefit; pharmacologic interventions take several weeks to reach maximum effect and are not curative.
• Treat secondary/contributing causes (UTI, constipation, poor mobility, contributing medications) before or alongside definitive incontinence-specific therapy.
• Document baseline frequency, urgency, and other symptoms so that improvement (or lack of it) can be objectively assessed at follow-up.
• Assess baseline cognition in older adults before starting an antimuscarinic, to allow later monitoring for treatment-associated cognitive change.
• Anticipate and address adherence challenges — both nonpharmacologic and pharmacologic treatments have real persistence problems in practice.

Pregnancy

Urinary incontinence before pregnancy is uncommon; the peripartum period is when many patients experience it for the first time, with stress incontinence the most common pattern and urgency/frequency increasing through pregnancy. The mechanism combines hormonal change, weight gain, and increased pressure on the bladder and pelvic floor. Risk factors for postpartum incontinence include an assisted vaginal delivery (forceps), oxytocin exposure in labour, and delivery of a larger infant. Management in pregnancy and the immediate postpartum period is preventative and non-pharmacologic — pelvic floor muscle training started during pregnancy and continued postpartum is effective and is the primary intervention; most patients experience resolution of symptoms after delivery, though the risk of long-term stress incontinence and nocturia is increased, especially after more than one delivery.

Breastfeeding

Incontinence itself does not affect the nursing infant. Avoid recommending fluid restriction as a treatment strategy during breastfeeding — reducing fluid intake can reduce milk production, and fluid restriction for incontinence has not been studied in this population.

Older adults and frail patients

Renal impairment

• Fesoterodine: do not exceed 4 mg once daily if creatinine clearance is under 30 mL/min.
• Solifenacin: do not exceed 5 mg once daily in severe renal impairment (creatinine clearance under 30 mL/min).
• Trospium: do not exceed 20 mg once daily (at bedtime) in severe renal impairment.
• Mirabegron: do not exceed 25 mg once daily in severe renal impairment; not recommended in end-stage renal disease or dialysis.
• Propiverine: do not exceed 30 mg once daily (the 45 mg strength should not be used) if creatinine clearance is under 30 mL/min.

Hepatic impairment

• Darifenacin and fesoterodine: avoid in severe hepatic impairment.
• Solifenacin: do not exceed 5 mg once daily in severe hepatic insufficiency.
• Mirabegron: do not exceed 25 mg once daily in moderate hepatic impairment; not recommended in severe hepatic impairment.
• Propiverine: not recommended in moderate or severe hepatic impairment.

Male patients

Overflow incontinence in men is most often related to bladder outlet obstruction from benign prostatic hyperplasia — manage the obstruction directly (see Lower Urinary Tract Symptoms and Benign Prostatic Hyperplasia). Stress incontinence in men occurs mainly after prostate surgery; pelvic floor muscle training before and immediately after prostatectomy is recommended, with a sling procedure an option for persistent post-prostatectomy stress incontinence once non-invasive measures have been tried.

Postmenopausal patients

Topical vaginal estrogen may be considered as an adjunct for postmenopausal urgency, stress, or mixed incontinence when vaginal atrophy is also present, though the evidence for benefit on incontinence itself is weak — the rationale is treating coexisting genitourinary syndrome of menopause rather than the incontinence directly. Systemic estrogen therapy (oral or transdermal) is not effective for incontinence and may worsen it — do not substitute a systemic product for a topical one. See the Menopause chapter for full estrogen-therapy dosing, safety, and counselling guidance.

Reassess symptom frequency/severity against the documented baseline at each follow-up, using the same bladder diary or symptom count used initially so improvement (or lack of it) is objectively comparable. For antimuscarinic or beta-3 agonist therapy, continue for at least 4-8 weeks before judging benefit, and reassess adherence and tolerability at that point — early discontinuation from side effects is common and should prompt a switch rather than simply stopping therapy without follow-up. In patients started on an antimuscarinic, monitor for constipation, cognitive change, and urinary retention (repeat PVR if retention is suspected), particularly in older adults; reassess cognition periodically against the pre-treatment baseline. Recheck blood pressure periodically in patients on mirabegron. For patients using a pessary or other vaginal device, arrange periodic device checks and vaginal examination. For stress incontinence managed with pelvic floor muscle training, reassess at 6-8 weeks, since this is the typical time to first benefit; continued improvement can occur for several months with adherence. Reinforce that pharmacologic therapy for incontinence is not curative and requires ongoing use to maintain benefit.

1. Confirm the diagnosis: reconfirm which type of incontinence is present, and specifically rule out overflow incontinence (check PVR) before continuing or escalating antimuscarinic/beta-3 agonist therapy.
2. Confirm and treat secondary/contributing causes that may not yet have been addressed — urinary tract infection, constipation, poorly controlled diabetes, and contributing medications.
3. Confirm adherence to nonpharmacologic therapy specifically — PFMT/bladder training needs a genuine 6-8 week trial with correct technique before being judged ineffective; consider a pelvic floor physiotherapy referral if self-directed exercise has not helped.
4. For urgency incontinence on pharmacotherapy without adequate benefit at 8 weeks: switch to a different agent, or switch class (from an antimuscarinic to mirabegron, or vice versa), rather than simply increasing the dose of a poorly tolerated agent.
5. Combine nonpharmacologic and pharmacologic therapy if either alone gives only partial benefit.
6. For stress incontinence refractory to an adequate PFMT trial: reassess for a vaginal device (pessary), or discuss duloxetine versus surgical referral based on patient preference and suitability for surgery.
7. For urgency incontinence refractory to an adequate trial of behavioural therapy plus at least one pharmacologic class: refer for onabotulinumtoxinA, sacral or tibial neuromodulation, or specialist urodynamic assessment.
8. For overflow incontinence not resolving with reversible-cause management: refer to urology for further evaluation of detrusor underactivity or bladder outlet obstruction, and ensure catheterization (intermittent preferred where feasible) is in place in the interim.

• Starting an antimuscarinic or beta-3 agonist for suspected overactive bladder without first ruling out overflow incontinence (elevated PVR) — this can precipitate urinary retention.
• Treating urgency incontinence with drug therapy before an adequate trial of bladder training — behavioural therapy is more effective than antimuscarinic therapy alone and should come first.
• Defaulting to oxybutynin in a frail or cognitively impaired older adult instead of a more selective antimuscarinic or mirabegron.
• Continuing an antimuscarinic or beta-3 agonist indefinitely without reassessing benefit at 4-8 weeks, or stopping therapy after a single side effect without trying dose reduction or a class switch.
• Missing a medication-induced or medication-aggravated cause (diuretics, alpha-blockers, sedative-hypnotics, opioids, anticholinergic medications used for other indications) before starting incontinence-specific drug therapy.
• Prescribing systemic estrogen therapy for incontinence — it is not effective and may worsen urgency incontinence; only topical/vaginal estrogen has a role, and only as an adjunct when vaginal atrophy coexists.
• Recommending aggressive fluid restriction — this can worsen constipation (itself a risk factor for incontinence) and, in a breastfeeding patient, reduce milk supply; a modest daytime reduction is reasonable, but complete restriction is not.
• Substituting a menstrual pad for a purpose-designed incontinence containment product, or using the wrong containment product for the patient's anatomy or type of incontinence.
• Not assessing baseline cognition before starting an antimuscarinic in an older adult, making later treatment-related cognitive change difficult to recognize.
• Attributing all incontinence in a frail older adult to "old age" without screening for the functional (mobility/cognitive/environmental) contributors that are often the most modifiable part of the problem.

How to use this table: Doses are adult doses and require patient-specific confirmation, including renal/hepatic adjustment. Confirm the type of incontinence before selecting any drug — antimuscarinics and beta-3 agonists are not appropriate for overflow incontinence. Select any drug name to open its complete Pharmasist Drug Database page.

Antimuscarinics (anticholinergics)

Considered 2nd line for urgency incontinence, after an adequate trial of bladder training. Do not use for overflow incontinence — every agent in this class can worsen urinary retention. Continue for at least 4-8 weeks before judging benefit; discontinue or switch if there is no benefit, or if side effects are not tolerable, at that point.

Beta-3 adrenergic agonists

Comparable efficacy to antimuscarinic therapy with essentially no anticholinergic burden — a reasonable 1st pharmacologic choice, and generally preferred over an antimuscarinic in frail or cognitively impaired older adults.^[3]

Vibegron is a newer beta-3 agonist with comparable efficacy and tolerability to mirabegron, including similarly minimal anticholinergic burden. It is approved and marketed in the United States and parts of Europe, but is not currently approved or marketed in Canada, so mirabegron remains the beta-3 agonist available in Canadian practice.

Botulinum toxin

Reserved for urgency incontinence/OAB refractory to behavioural therapy and at least one pharmacologic class. Administered by a specialist via cystoscopy — not a community pharmacy dispensing decision, but pharmacists should recognize it as the next step and counsel appropriately.

Serotonin-norepinephrine reuptake inhibitor (stress incontinence, off-label)

Duloxetine is approved in Canada for depression, anxiety, and pain — not for stress incontinence. Evidence shows a reduction in incontinence episodes and improved quality of life, but benefit is modest and discontinuation due to side effects is common.^[6]

Vaginal estrogen (adjunct for coexisting atrophy)

Evidence for benefit on incontinence itself is weak; use is justified mainly by treating coexisting genitourinary syndrome of menopause in a patient with urgency, stress, or mixed incontinence. See the Menopause chapter for complete estrogen-therapy dosing, safety, and counselling guidance not specific to incontinence.

Evidence note: Drug inventory, dosing, adverse effects, and comments reflect standard Canadian product labelling, cross-checked against the AUA/SUFU and CUA guidelines cited throughout this chapter.^[7]