What medication is suitable for an 87-year-old male with urinary frequency and increased thirst, without Diabetes Mellitus (DM)?

From the Guidelines

For an 87-year-old male experiencing urinary frequency and increased thirst without diabetes mellitus, I recommend starting with mirabegron 25mg once daily, as it has been shown to improve frequency, urgency, and urinary incontinence episodes compared to placebo or tolterodine 1. This medication is a beta-3 agonist, which is well-tolerated in the elderly and in patients with multiple comorbidities, but it is contraindicated in patients with severe uncontrolled hypertension 1. Some key points to consider when prescribing mirabegron include:

• Monitoring for potential side effects such as hypertension, UTIs, headache, and nasopharyngitis 1
• Ruling out urinary tract infection with a urinalysis and culture before starting medication
• Evaluating for other potential causes including benign prostatic hyperplasia, which might require alpha-blockers like tamsulosin 0.4mg daily instead
• Considering basic metabolic panel and renal function tests to investigate increased thirst without diabetes
• Implementing conservative measures alongside medication, such as limiting fluid intake in the evening, avoiding caffeine and alcohol, and scheduled voiding every 2-3 hours
• If symptoms don't improve within 2-4 weeks, consider urology referral for further evaluation including possible cystoscopy or urodynamic studies. It's also important to note that long-term data on the efficacy and safety of mirabegron in men of any age with LUTS are not available, so close monitoring of the patient's condition is necessary 1.

From the FDA Drug Label

Of 5,648 patients who received mirabegron monotherapy in the phase 2 and 3 studies for OAB, 2,029 (35.9%) were 65 years of age or older, and 557 (9. 9%) were 75 years of age or older. No overall differences in safety or effectiveness were observed between patients younger than 65 years of age and those 65 years of age or older in these studies. Mirabegron is an agonist of the human beta-3 adrenergic receptor (AR) as demonstrated by in vitro laboratory experiments using the cloned human beta-3 AR. Mirabegron relaxes the detrusor smooth muscle during the storage phase of the urinary bladder fill-void cycle by activation of beta-3 AR which increases bladder capacity

Mirabegron may be considered for the treatment of an 87-year-old male with urinary frequency and increased thirst, as no overall differences in safety or effectiveness were observed between patients younger than 65 years of age and those 65 years of age or older in the studies. However, it is essential to consider the patient's overall health and potential interactions with other medications. The patient's symptoms suggest overactive bladder (OAB), and mirabegron has been shown to increase bladder capacity by relaxing the detrusor smooth muscle. 2

From the Research

Treatment Options for Urinary Frequency and Increased Thirst in an 87-year-old Male

• The patient's symptoms of urinary frequency and increased thirst, without diabetes mellitus, could be indicative of overactive bladder (OAB) syndrome 3.
• Anticholinergic drugs are a common treatment for OAB symptoms, and several options are available, including oxybutynin, tolterodine, solifenacin, and fesoterodine 4, 3, 5.

Comparison of Anticholinergic Drugs

• Tolterodine and oxybutynin have been shown to be effective in treating OAB symptoms, with tolterodine having a better tolerability profile and fewer adverse events, such as dry mouth 4, 5.
• Solifenacin has been shown to be more effective than tolterodine in improving quality of life and reducing leakage episodes, but may have a higher risk of dry mouth 4.
• Fesoterodine has been shown to be more effective than extended-release tolterodine in improving quality of life and reducing leakage episodes, but may have a higher risk of adverse events and dry mouth 4.

Considerations for Elderly Patients

• When selecting an anticholinergic agent for an elderly patient, it is essential to consider the potential for cognitive adverse events, sleep disturbances, and interactions with other medications 3.
• Trospium chloride may be a suitable option for elderly patients, as it is not extensively metabolized in the liver and has a lower risk of cognitive adverse events and sleep disturbances 3.

Combination Therapy

• Combination therapy with an alpha-blocker, such as tamsulosin, and an anticholinergic agent, such as solifenacin, may be effective in treating storage symptoms and improving quality of life in patients with benign prostatic hyperplasia (BPH) and OAB symptoms 6, 7.
• Initial combined therapy with tamsulosin and solifenacin may help improve storage symptoms and quality-of-life scores earlier in patients with BPH and OAB symptoms 7.