What are the medications for detrusor (detrusor muscle) overactivity or urinary bladder spasm?

From the Guidelines

The most effective medication for bladder spasms is a combination of solifenacin (5 mg) and mirabegron (50 mg), which has been shown to be statistically superior to monotherapy in reducing urinary incontinence episodes and micturitions per 24 hours 1. Medications for bladder spasms typically include anticholinergics, beta-3 agonists, and muscle relaxants.

• First-line anticholinergic options include oxybutynin (5mg 2-3 times daily), tolterodine (2-4mg daily), solifenacin (5-10mg daily), and trospium (20mg twice daily).
• These work by blocking acetylcholine receptors, reducing involuntary bladder muscle contractions.
• Beta-3 agonists like mirabegron (25-50mg daily) relax the bladder by activating beta-3 adrenergic receptors.
• For acute spasms, muscle relaxants such as flavoxate (100-200mg 3-4 times daily) or diazepam (2-5mg 2-3 times daily) may provide temporary relief.
• Patients should start at lower doses and increase as needed while monitoring for side effects like dry mouth, constipation, and blurred vision with anticholinergics, or potential hypertension with mirabegron.
• Lifestyle modifications should accompany medication, including timed voiding, reducing caffeine and alcohol intake, and pelvic floor exercises.
• If symptoms persist after 4-6 weeks of treatment, dosage adjustments or medication changes may be necessary.
• Patients with glaucoma, urinary retention, or certain gastrointestinal conditions should use anticholinergics cautiously and discuss alternatives with their healthcare provider. The combination of solifenacin and mirabegron has been evaluated in several studies, including the BESIDE trial, which showed that the combination was superior to monotherapy in reducing urinary incontinence episodes and micturitions per 24 hours 1. Additionally, the SYNERGY II trial found that the combination of solifenacin and mirabegron was statistically superior to mirabegron and solifenacin monotherapy for decreasing the number of incontinence episodes and micturitions 1. A recent summary paper on the 2023 European Association of Urology guidelines on the management of non-neurogenic male lower urinary tract symptoms also supports the use of combination therapy with solifenacin and mirabegron 1. Overall, the evidence suggests that the combination of solifenacin and mirabegron is a effective treatment option for bladder spasms, and should be considered as a first-line treatment.

From the FDA Drug Label

Mirabegron extended-release tablets are a beta-3 adrenergic agonist indicated for the treatment of: Overactive bladder (OAB) in adult patients with symptoms of urge urinary incontinence, urgency, and urinary frequency. Mirabegron extended-release tablets are indicated for the treatment of OAB in adult patients with symptoms of urge urinary incontinence, urgency, and urinary frequency. Mirabegron extended-release tablets are indicated for the treatment of NDO in pediatric patients aged 3 years and older and weighing 35 kg or more.

Medications for bladder spasm: Mirabegron is used to treat overactive bladder (OAB) with symptoms of urge urinary incontinence, urgency, and urinary frequency in adults, and neurogenic detrusor overactivity (NDO) in pediatric patients aged 3 years and older and weighing 35 kg or more 2, 2, 2.

• Key points:
  • Mirabegron is a beta-3 adrenergic agonist.
  • It is used to treat OAB and NDO.
  • The recommended starting dose is 25 mg orally once daily, which may be increased to 50 mg orally once daily after 4 to 8 weeks.

From the Research

Medications for Bladder Spasm

• The primary medications used to treat bladder spasm, also known as overactive bladder, are anticholinergic drugs 3, 4, 5, 6, 7.
• These medications work by inhibiting the bladder muscarinic receptors, which helps to reduce the symptoms of urgency, frequency, and urge incontinence.

Types of Anticholinergic Drugs

• Oxybutynin and tolterodine are two of the most commonly used anticholinergic drugs for the treatment of overactive bladder 3, 4, 6.
• Solifenacin, darifenacin, and trospium are newer anticholinergic drugs that have been shown to be effective in treating overactive bladder with fewer side effects 3, 4, 7.
• Fesoterodine is another anticholinergic drug that has been shown to be effective in treating overactive bladder, but it has a higher risk of withdrawal due to adverse events and dry mouth 3.

Comparison of Anticholinergic Drugs

• Tolterodine has been shown to be better tolerated than oxybutynin, with fewer adverse effects such as dry mouth 3, 6.
• Solifenacin has been shown to be more effective than tolterodine in reducing symptoms of overactive bladder, but it has a higher risk of dry mouth 3.
• Fesoterodine has been shown to be more effective than extended release tolterodine, but it has a higher risk of withdrawal due to adverse events and dry mouth 3.

Considerations for Elderly Patients

• Antimuscarinic therapy is often underutilized in elderly patients due to concerns about anticholinergic adverse events, such as dry mouth, and potential interactions with existing pharmacotherapy 7.
• Trospium chloride and darifenacin may be safer options for elderly patients due to their lower risk of cognitive adverse events and interactions with other medications 7.