The optimal medication for women with nocturia remains uncertain. This clinical trial aimed to determine the most effective medication for women with overactive bladder and nocturia. Its primary objectives were to answer the following questions:

Which medication is most effective for women with nocturia? Which medication has the least effect on heart rate variability in women with nocturia?

We will conduct a prospective randomized controlled study in the outpatient clinic of Department of Obstetrics and Gynecology of Far Eastern Memorial Hospital. All female patients with overactive bladder syndrome enrolled in the study will be requested to fill in the questionnaires and before taking the drug and four weeks and twelve weeks after taking the medication. In addition, measurement of heart rate variability will be performed before and twelve weeks after taking the medication. All enrolled women will be randomized to receive nighttime mirabegron, solifenacin, tolterodine or oxybutynin for 12 weeks.

The aims of this study is to obtain the impact of nighttime dosing of mirabegron, solifenacin, tolterodine or oxybutynin versus combined therapy on nocturia, psychologic distress, sexual function, cognition, heart rate variability and bladder blood perfusion in women with overactive bladder syndrome.

Inclusion Criteria:

• >18 years old.
• female patients with overactive bladder syndrome

Exclusion Criteria:

• Clinically significant dysuria (inability to urinate, difficulty urinating).
• Severe stress urinary incontinence (urinary incontinence caused by coughing).
• Mixed urinary incontinence mainly caused by stress urinary incontinence (urinary incontinence caused by coughing as the main symptom).
• Contraindications to antimuscarinic drugs or adrenergic receptor agonists.