What is the recommended treatment and dosage of Trospium for overactive bladder symptoms?

Trospium for Overactive Bladder: Treatment and Dosing

Recommended Dosage

The recommended dose of trospium chloride extended-release is 60 mg once daily, taken in the morning with water on an empty stomach, at least one hour before a meal. 1

• The immediate-release formulation is dosed at 20 mg twice daily 2, 3
• Extended-release formulation provides comparable efficacy to twice-daily dosing with lower rates of dry mouth 4
• Trospium is not recommended for patients with severe renal impairment (creatinine clearance <30 mL/min) 1

Position in Treatment Algorithm

Trospium should be offered as second-line therapy after behavioral interventions, though beta-3 agonists are typically preferred before antimuscarinic medications due to lower cognitive risk. 5, 6

First-Line Therapy

• Behavioral therapies (bladder training, pelvic floor muscle training, fluid management) must be offered first to all patients 5
• These interventions are risk-free and as effective as antimuscarinics 7

Second-Line Pharmacotherapy

• Both antimuscarinic medications (including trospium) and beta-3 agonists improve urgency, frequency, and urgency urinary incontinence 5
• Beta-3 agonists are typically preferred before antimuscarinics due to dementia risk with chronic antimuscarinic use 5, 6
• However, trospium's unique quaternary ammonium structure results in minimal central nervous system penetration, potentially offering advantages over other antimuscarinics 3, 4

Efficacy Profile

Trospium demonstrates significant improvements in all primary overactive bladder symptoms, with benefits apparent within the first week of treatment. 2, 4, 8

• Reduces daily toilet voids by approximately 2-3 episodes compared to baseline 1, 4, 8
• Decreases urgency urinary incontinence episodes by 30-40% 2, 4, 8
• Increases voided volume per void by 20-30 mL 1, 4
• Improvements in quality of life measures are significant and sustained through 12 weeks 9

Critical Contraindications and Warnings

Trospium is absolutely contraindicated in patients with urinary retention, gastric retention, uncontrolled narrow-angle glaucoma, or known hypersensitivity. 1

Use with Extreme Caution In:

• Patients with narrow-angle glaucoma (only if approved by ophthalmologist) 5, 1
• Impaired gastric emptying or gastrointestinal obstructive disorders 5, 1
• History of urinary retention or clinically significant bladder outflow obstruction 5, 1
• Severe renal impairment (contraindicated if CrCl <30 mL/min) 1

Cognitive Risk Considerations

• Discuss potential dementia and cognitive impairment risk with all patients, particularly elderly 5
• While trospium has minimal CNS penetration compared to other antimuscarinics, the association between antimuscarinic medications and incident dementia may be cumulative and dose-dependent 5, 3
• Consider beta-3 agonists preferentially in elderly patients at risk for cognitive decline 6, 10

Common Adverse Effects

The most common side effects are dry mouth (9-13%) and constipation (7-9%), occurring at lower rates than many other oral antimuscarinics. 4, 8

• Dry mouth: 8.7-12.9% with trospium vs 3-4.6% with placebo 4, 8
• Constipation: 7.5-9.4% with trospium vs 1.3-1.8% with placebo 4, 8
• Central nervous system adverse events are rare (headache 1.0% vs placebo 2.6%) 4
• Angioedema can occur, even after first dose; discontinue immediately if tongue, hypopharynx, or larynx involvement occurs 1

Dose Adjustment Considerations

In elderly patients already on trospium with inadequate response, consider dose optimization if not at maximum dose, or switch to alternative antimuscarinic or beta-3 agonist. 10

• Trospium pharmacokinetics are similar in older (≥65 years) and younger patients 1
• No dose adjustment needed for mild-to-moderate hepatic impairment 1
• Avoid in severe renal impairment due to 4.2-fold increase in AUC and prolonged half-life 1

Treatment Failure Management

If trospium is ineffective or poorly tolerated, switch to another antimuscarinic or beta-3 agonist before considering third-line therapies. 7, 10

• Combination therapy with behavioral interventions and pharmacotherapy may provide additive benefits 5
• Third-line options include sacral neuromodulation, tibial nerve stimulation, or onabotulinumtoxinA bladder injections 7, 10
• Schedule follow-up within 4-8 weeks to assess treatment response using bladder diary 10

Key Clinical Pearls

• Trospium is not metabolized by cytochrome P450, resulting in lower drug interaction potential 3
• Excreted mainly unchanged in urine, providing local bladder activity 3
• Extended-release formulation achieves lowest reported dry mouth rate in the oral antimuscarinic class 4
• Must be taken on empty stomach (at least 1 hour before meals) for optimal absorption 1