From the Guidelines
For a geriatric female on Myrbetriq (mirabegron) 50 mg daily with persistent urinary frequency and urgency, I recommend further evaluation with urinalysis (UA) to rule out urinary tract infection, as suggested by the most recent guidelines 1. This approach is crucial because urinary tract infections can present atypically in older adults, with symptoms such as altered mental status, functional decline, or fatigue, rather than the typical symptoms of dysuria, frequency, and urgency 1. The UA is essential for diagnosing UTI, especially since the specificity of urine dipstick tests can be low in the elderly, ranging from 20% to 70% 1. Additionally, a post-void residual (PVR) measurement should be considered to assess bladder emptying, as urinary retention can be a contributing factor to the patient's symptoms.
Other management options could include:
- Trying an anticholinergic medication such as solifenacin 5-10 mg daily or oxybutynin 5 mg twice daily, though these carry a higher risk of cognitive side effects in geriatric patients 1.
- Combination therapy with mirabegron plus an anticholinergic could also be considered, weighing the potential benefits against the risk of increased side effects.
- Non-pharmacological approaches should be emphasized, including pelvic floor physical therapy, timed voiding, fluid management, and bladder training, as these form the foundation of overactive bladder management in geriatric patients 1.
- If symptoms persist, referral to urology for possible urodynamic testing would be appropriate to better characterize the bladder dysfunction. While checking A1C is reasonable to rule out diabetes as a contributor to urinary symptoms, a more comprehensive urological workup would be the priority, given the patient's current symptoms and the potential for underlying conditions that could be contributing to her urinary frequency and urgency 1. Behavioral modifications should be continued throughout treatment, as they are crucial for managing overactive bladder in geriatric patients.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Diagnostic Tests
- Urinalysis (UA) is a common diagnostic test to evaluate urinary frequency and urgency in patients, including those taking Myrbetriq (mirabegron) 2, 3.
- Hemoglobin A1C (A1C) test may be relevant in patients with urinary frequency and urgency to rule out diabetes, a potential underlying cause of these symptoms 2, 3.
Management Options
- If Myrbetriq 50 mg daily is not effective, alternative management options may include:
- Increasing the dose of Myrbetriq to 100 mg daily, as some studies have shown significant improvements in symptoms at this dose 3, 4.
- Adding other medications, such as antimuscarinics or alpha-blockers, to the treatment regimen, as some studies have shown efficacy in combination therapy 4, 5.
- Considering alternative treatments, such as behavioral therapies or other pharmacological agents, as some patients may not respond to Myrbetriq or may experience adverse effects 2, 3.
Special Considerations
- In geriatric patients, such as the one described, it is essential to carefully evaluate the potential benefits and risks of treatment, including the potential for adverse effects or interactions with other medications 2, 3.
- Regular monitoring of urinary symptoms, as well as potential adverse effects, is crucial to ensure optimal management and minimize the risk of complications 2, 3.