Current optimal pharmacologic therapies for overactive bladder

ABSTRACT

Introduction

Overactive bladder (OAB) is a common syndrome in adults. Current pharmacologic treatment includes antimuscarinic agents and β-3 adrenoceptor agonists. For non-responders to oral medication, intravesical injection of botulinum toxin A (BoNT-A) is an effective option. However, these treatments have potential adverse events and should be cautiously selected for appropriate patients. This review presents the recently published results of clinical trials and studies for patients with OAB and the underlying pathophysiology of OAB. Appropriate medical therapy based on pathophysiology of OAB is also presented.

Areas covered

Literature search from Pubmed from 2001 to 2023 including clinical background, pharmacology, and clinical studies for OAB medications.

Expert opinion

Treatment of OAB syndrome with any antimuscarinic or β-3 adrenoceptor agonist is feasible as a first-line approach. For patients with suboptimal therapeutic effect to full-dose antimuscarinics or mirabegron, combination with both drugs can improve efficacy. Intravesical BoNT-A 100-U injection provides therapeutic effects for refractory OAB. Patients who are refractory to initial pharmacotherapies should be investigated for the underlying pathophysiology; then an appropriate medication can be added, such as an α1-blocker or anti-inflammatory agents. Patient education about behavioral modification and therapies should always be provided with oral medication or BoNT-A injection for OAB patients.

Plain Language Summary

Overactive bladder (OAB) causes urgency, frequency, and nocturia, and greatly impacts quality of life. Pharmacological treatment with antimuscarinics, beta-3 adrenoceptor agonists, or in combination can effective improve OAB symptoms. In cases of treatment failure, searching for underlying causes and switching to the other treatment modalities such as Botox injection are also feasible to relieve the bothersome bladder symptoms.

KEYWORDS:

• Urinary incontinence
• bladder
• medical treatment
• pharmacotherapy
• pathophysiology

Article highlights

• Treatment of overactive bladder (OAB) syndrome with any antimuscarinic or β-3 adrenoceptor agonists is feasible as a first-line approach.

• The initial results of a Taiwanese study of low-dose mirabegron treatment show it is effective for OAB, bladder outlet obstruction (BOO) or non-BOO, for patients across the age spectrum (youth to older adults), for those with detrusor overactivity or detrusor overactivity and low detrusor contractility, and for patients with central nervous system lesions.

• In patients who have less favorable response to antimuscarinics, an immediate change to mirabegron resulted in a better outcome.

• In patients who are stably treated with antimuscarinics, shifting to mirabegron may decrease adverse events and have a similar treatment effect.

• Evidence have shown the drug related adverse events are less reported and adherence rate is higher in mirabegron than that in antimuscarinics. Therefore, mirabegron should be considered first in selecting medication for patients with OAB.

• Starting with a low dose of mirabegron (25 mg) is effective for OAB. For patients with suboptimal effect to mirabegron 25 mg, escalating to mirabegron 50 mg or changing to combination mirabegron and antimuscarinics can improve therapeutic efficacy.

• Intravesical botulinum toxin A injection provides therapeutic effects on OAB refractory to antimuscarinics or a β-3 adrenoceptor agonist.

• Men with persistent OAB after medical treatment for lower urinary tract symptoms, BOO should be considered and adequately treated, although adding mirabegron as the first-line medication is also effective.

• Treatment duration of 3 months for OAB is adequate for most patients. If relapse occurs after discontinuation, life-long treatment may be necessary.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

A reviewer on this manuscript has disclosed that they have done research studies supported by Astellas for Mirabegron. Peer reviewers on this manuscript have no other relevant financial relationships or otherwise to disclose.

Additional information

Funding

This paper was funded by the Buddhist Tzu Chi Medical Foundation, Hualien Tzu Chi Hospital. Grand numbers [TCMF-SP-112-01 and TCMF-MP-110-03-01].