What is the recommended dose and treatment regimen for Trospium (Trospium chloride) in patients with overactive bladder?

Recommended Dose and Treatment Regimen for Trospium Chloride in Overactive Bladder

The recommended dosage of Trospium Chloride Extended-Release is one 60 mg capsule taken once daily in the morning on an empty stomach, at least one hour before a meal. 1

Dosing Guidelines

• Trospium is available in two formulations:
  • Extended-release: 60 mg once daily in the morning 1
  • Immediate-release: 20 mg twice daily 2, 3
• The medication should be taken with water on an empty stomach, at least one hour before a meal to ensure optimal absorption 1
• Food significantly reduces trospium bioavailability, making the timing of administration important 4
• Peak plasma concentrations are attained approximately 5-6 hours after oral administration 4

Special Population Considerations

• Renal Impairment: Trospium is not recommended for patients with severe renal impairment (creatinine clearance less than 30 mL/minute) 1
• Age and Sex: Dosage adjustments based on age or sex are generally not warranted 4
• Elderly Patients: May be preferred in elderly patients due to minimal central nervous system effects as it doesn't significantly cross the blood-brain barrier 4, 5

Contraindications

Trospium is contraindicated in patients with:

• Urinary retention 1
• Gastric retention 1
• Uncontrolled narrow-angle glaucoma 1
• Known hypersensitivity to the drug or its ingredients 1

Clinical Efficacy

• Trospium has demonstrated effectiveness in reducing:
  • Frequency of urination 2, 3
  • Urgency severity 2, 3
  • Urge incontinence episodes 2, 3
• Effects typically begin within the first week of treatment and are sustained throughout the treatment period 2, 3
• Trospium has shown comparable efficacy to other antimuscarinic agents such as oxybutynin and tolterodine 4, 6

Common Side Effects

• Dry mouth (10.7% with extended-release formulation) 1
• Constipation (8.5% with extended-release formulation) 1
• Other potential side effects include dyspepsia, abdominal pain, and nausea 4
• The extended-release formulation has a lower rate of dry mouth compared to the immediate-release formulation 5

Important Monitoring and Precautions

• Measure post-void residual (PVR) in patients suspected of having a higher risk of urinary retention 7
• Use with extreme caution in patients with impaired gastric emptying or history of urinary retention 7
• Monitor for angioedema, which has been reported with trospium use 1
• Avoid alcohol within 2 hours of trospium administration 1

Treatment Context in OAB Management

• Trospium is considered a second-line therapy for OAB after behavioral therapies 7
• Behavioral therapies (bladder training, pelvic floor muscle training, fluid management) should be offered as first-line treatment 7
• Trospium may be combined with behavioral therapies for enhanced effectiveness 7
• If patients experience inadequate symptom control or unacceptable side effects with trospium, consider dose modification or switching to a different antimuscarinic or β3-adrenoceptor agonist 7

Drug Interactions

• Trospium undergoes minimal metabolism by the hepatic cytochrome P450 system, resulting in few metabolic drug interactions 4
• Some drugs actively secreted by the kidney may interact with trospium by competing for renal tubular secretion 1
• Concomitant use with antacids may affect trospium exposure in some individuals 1
• Concomitant use with metformin immediate-release tablets may reduce exposure and peak concentration of trospium 1

Remember that treatment selection should involve shared decision-making between the clinician and patient, taking into account the patient's symptoms, preferences, and potential side effects 7.