Is topical conjugated estrogen (estrogen) effective for treating overactive bladder?

Effectiveness of Topical Conjugated Estrogen for Overactive Bladder

Topical conjugated estrogen may provide modest benefit for overactive bladder symptoms, particularly when used vaginally, but should not be considered first-line therapy due to limited and mixed evidence. 1

Evidence Assessment

Efficacy of Topical Estrogen for OAB

• Vaginal estrogen formulations: Evidence shows some improvement in urinary incontinence with vaginal estrogen tablets and ovules compared to placebo 1

  • Vaginal estrogen tablets increased continence with a Number Needed to Treat Benefit (NNTB) of 5 1
  • However, the overall evidence was deemed insufficient to determine the effectiveness of topical estrogen therapies for improving urinary incontinence 1

• Route of administration matters:

  • Vaginal estrogen formulations showed increased continence and improved urinary incontinence 1
  • In contrast, transdermal estrogen patches were associated with worsened urinary incontinence 1
  • Local administration may be more beneficial than systemic administration 2

Specific Studies on Topical Estrogen for OAB

• A 2018 study found that vaginal estriol gel improved both subjective OAB symptoms and urodynamic parameters including first desire to void and maximum cystometric capacity 3

• A 2020 study demonstrated that vaginal estrogen therapy increased Lactobacillus in the urine of postmenopausal women with OAB symptoms, which correlated with modest improvement in urgency incontinence symptoms 4

• A 2016 study showed that combining fesoterodine (an antimuscarinic) with topical vaginal estrogen improved OAB symptoms and reduced total micturitions compared to fesoterodine alone 5

Treatment Algorithm for OAB

1. First-line treatments (should be tried before considering estrogen):

   • Behavioral therapies (recommended for all OAB patients) 1
     • Fluid management
     • Caffeine reduction
     • Physical activity/exercise
     • Dietary modifications
     • Bladder training

2. Second-line treatments:

   • Pharmacotherapy with antimuscarinic medications or beta-3 agonists
   • Consider topical vaginal estrogen as an adjunct therapy, particularly in postmenopausal women with concurrent vaginal atrophy symptoms

3. Combination approaches:

   • For inadequate response to monotherapy, consider combining behavioral therapy with pharmacotherapy 1
   • Topical vaginal estrogen may be added to antimuscarinic therapy for potentially enhanced effects 5

Important Clinical Considerations

• Patient selection: Topical estrogen may be most beneficial for postmenopausal women with concurrent vaginal atrophy and OAB symptoms 4, 3

• Monitoring: When using topical estrogen, monitor for:

  • Changes in OAB symptoms
  • Improvement in vaginal symptoms
  • Any adverse effects

• Common pitfalls:

  • Failing to differentiate between stress and urgency incontinence before treatment selection 6
  • Using estrogen alone when combination therapy might be more effective 5
  • Not allowing sufficient time for topical estrogen to take effect (studies typically evaluated outcomes after 12 weeks) 5, 4, 3

• Shared decision-making: Discuss the modest potential benefits and limitations of topical estrogen therapy with patients, as well as alternative treatment options 1

Conclusion on Topical Estrogen for OAB

While topical conjugated estrogen, particularly vaginal formulations, may provide some benefit for overactive bladder symptoms, the evidence is mixed and limited. Behavioral therapies should be offered first, with pharmacologic options including antimuscarinic agents or beta-3 agonists as second-line treatments. Topical estrogen may be considered as an adjunctive therapy, especially in postmenopausal women with concurrent vaginal atrophy.