When do you give oxybutynin (anticholinergic medication) to patients with overactive bladder?

When to Give Oxybutynin for Overactive Bladder

Oxybutynin should be prescribed as a second-line therapy for overactive bladder (OAB) after behavioral therapies have failed or provided inadequate response, or it can be used in combination with behavioral therapies. 1

First-Line Therapy Before Oxybutynin

• Behavioral therapies should always be offered first to all patients with OAB before initiating oxybutynin 1
• These first-line interventions include:
  • Bladder training
  • Bladder control strategies
  • Pelvic floor muscle training
  • Fluid management 1
• Behavioral treatments are preferred initially because they are risk-free, can be tailored to individual patients, and have comparable effectiveness to antimuscarinic medications in reducing OAB symptoms 1

Specific Indications for Oxybutynin

• Oxybutynin is indicated for relief of symptoms of bladder instability associated with voiding in patients with uninhibited neurogenic or reflex neurogenic bladder 2
• These symptoms include:
  • Urgency
  • Frequency
  • Urinary leakage
  • Urge incontinence
  • Dysuria 2
• Patients who continue to experience bothersome OAB symptoms despite first-line behavioral interventions are candidates for oxybutynin therapy 1

Contraindications and Precautions

• Oxybutynin should not be used in patients with:
  • Narrow-angle glaucoma (unless approved by a treating ophthalmologist) 1
  • Impaired gastric emptying 1
  • History of urinary retention 1
• Patients at risk for gastric emptying problems should receive clearance from a gastroenterologist before starting oxybutynin 1
• Post-void residual (PVR) assessment may be useful in patients suspected of higher risk of urinary retention 1

Formulation Considerations

• Transdermal preparations of oxybutynin may be offered if dry mouth is a concern with oral formulations 1
• Extended-release formulations provide smoother plasma concentration profiles and once-daily dosing, which may improve adherence and reduce side effects 3
• The extended-release formulation offers greater flexibility in dosage (5-30 mg/day) than other available treatment options 3

Monitoring and Follow-up

• Monitor for common side effects, which include:
  • Dry mouth
  • Constipation
  • Dry eyes
  • Blurred vision
  • Dyspepsia
  • Urinary tract infection
  • Urinary retention
  • Impaired cognitive function 1
• Consider that beta-3 agonists are typically preferred before antimuscarinic medications like oxybutynin due to lower cognitive risk 1

Treatment Failure and Next Steps

• If oxybutynin is ineffective or poorly tolerated, consider:
  • Trying another antimuscarinic medication
  • Switching to a beta-3 agonist medication 1
• For patients who fail to respond to second-line pharmacotherapy, referral to a specialist for third-line therapies may be necessary, including:
  • Sacral neuromodulation
  • Tibial nerve stimulation
  • Intradetrusor botulinum toxin injection 1

Special Populations

• Oxybutynin has shown promising results in both adult and pediatric patients with neurogenic bladder dysfunction secondary to neuronal injury 3
• Patients with more severe symptoms typically experience greater symptom reductions with antimuscarinic therapy 1
• While effective in ambulatory elderly patients, oxybutynin appears less effective in institutionalized elderly individuals 4