Inclusion Criteria:
* Aged 60 years or older at the time of enrollment
* Female sex at birth, without surgical or hormonal gender re-assignment therapy
* Able to walk to the bathroom and use the toilet without assistance
* Report urinary incontinence starting at least 3 months prior to screening
* Report that at least half of incontinence episodes occur with a sudden or strong sensation of urgency
* Report 2 or more urgency incontinence episodes over a 7-day period
* Willing to provide informed consent and adhere to study procedures throughout the length of the study
Exclusion Criteria:
* Prior clinician diagnosis of dementia, or a Montreal Cognitive Assessment (MOCA) score of 17 or lower on screening cognitive evaluation
* Current use of anticholinergic, beta-3-adrenergic agonist, or other medication designed to improve urgency incontinence symptoms, or use in the past 1 month
* Initiation, discontinuation, or dose change of dementia medications (such as donepezil, galantamine, memantine, rivastigmine) in the past 1 month (but candidates on stable doses are eligible)
* Initiation, discontinuation, or dose change of other drugs with strong anticholinergic effects (based on the Beers List) in the past 1 month (but candidates on stable doses are eligible)
* Initiation, discontinuation, or dose change of other drugs that can affect urinary frequency, including diuretics, in the past 1 month (but candidates on stable doses are eligible)
* Current urinary tract infection (UTI) based on screening urinalysis and culture (but candidates can re-present for re-screening after undergoing treatment for UTI)
* History of allergy or sensitivity to either of the study medications or an ingredient in the placebo or study medication capsule
* Severe hepatic impairment (Child-Pugh score B or greater) or renal impairment (creatinine clearance \<30 mL/min) as a contraindication to both study medications
* Current bladder obstruction or urinary retention (defined by symptoms suggesting difficulty emptying the bladder in addition to postvoid residual urine volume greater than 150 cc by portable bladder ultrasound)
* Uncontrolled hypertension (based on measured systolic blood pressure greater than 180 or diastolic blood pressure greater than 110 mmHg) as a contraindication to beta-3-adrenergic therapy
* Self-reported history of gastric retention, uncontrolled narrow angle glaucoma, myasthenia gravis, severe ulcerative colitis, or toxic megacolon as contraindications for anticholinergic bladder therapy
* Use of drugs with adverse interactions with one of the study medications in the past 1 month, including potent CYP3A4 inhibitors, hepatic enzyme metabolism inducers, narrow therapeutic index drugs metabolized by CYP2D6, or intention to start taking one of these medications during the study treatment period
* History of bladder surgery, invasive intra-vesical therapy, or bulk bladder injections in the past 3 months (more remote surgery will not be exclusionary), or intention to undergo one of these procedures in the study treatment period
* Use of other specialized incontinence therapy (electrostimulation, pelvic physiotherapy, formal behavioral therapy overseen by certified practitioners) in the past 3 months (more remote therapy will not be exclusionary), or intention to undergo one of these procedures in the study treatment period
* Inability to sign informed consent or complete questionnaires, interviews, or study testing in English
* Other condition that would prevent the participant from completing study procedures, in the opinion of the investigators (e.g., uncontrolled psychosis)
