Tolterodine: a clinical review

Area of Science:

• Urology
• Pharmacology
• Clinical Trials

Background:

• Overactive bladder (OAB) significantly impacts quality of life.
• Existing pharmacotherapy for OAB has limitations regarding efficacy and side effects.
• Tolterodine emerged as a potential treatment option requiring thorough evaluation.

Purpose of the Study:

• To review clinical trials on the efficacy and safety of tolterodine for overactive bladder.
• To compare tolterodine's safety and efficacy against previously available pharmacotherapy, specifically oxybutynin.

Main Methods:

• Systematic review of English language randomized controlled trials (RCTs) from MEDLINE (1966-present) using the keyword 'tolterodine'.
• Included 10 RCTs with durations of 2-12 weeks, comparing tolterodine (0.5-4 mg bid or 4 mg ER daily) against placebo, oxybutynin (5 mg bid or tid), or different tolterodine formulations/doses.
• Analyzed parameters including voiding frequency, incontinence episodes, urodynamic measures, and adverse events.

Main Results:

• Tolterodine demonstrated significant improvement over placebo in OAB symptoms and urodynamic parameters.
• Tolterodine 2 mg bid showed equal efficacy to oxybutynin 5 mg tid.
• Adverse events, primarily dry mouth, were less frequent and severe with tolterodine 2 mg bid compared to oxybutynin 5 mg tid.
• Extended-release tolterodine showed comparable efficacy with potentially fewer side effects than immediate-release.
• High doses of tolterodine (4 mg bid) were associated with urinary retention.

Conclusions:

• Tolterodine 2 mg bid is an effective and well-tolerated alternative to oxybutynin 5 mg tid for managing overactive bladder.
• Tolterodine offers a favorable safety profile, particularly regarding the incidence and severity of dry mouth.
• Extended-release formulations may offer an improved efficacy and tolerability balance.