What considerations are necessary before adding anticholinergic (anticholinergic) medications for Overactive Bladder (OAB) in males?

From the Guidelines

Before adding anticholinergic medications for overactive bladder (OAB) in males, it is crucial to rule out bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH) and assess post-void residual (PVR) volume, as anticholinergics can worsen urinary retention in these patients 1. When considering anticholinergic therapy, several factors should be taken into account:

• A thorough evaluation including urodynamic studies, post-void residual measurement, and prostate assessment is essential to determine the presence of BOO or BPH.
• Combination therapy with an alpha-blocker (such as tamsulosin 0.4mg daily) should be considered if BPH is present, as it can help alleviate symptoms of both conditions 1.
• Common anticholinergics include oxybutynin (5mg 2-3 times daily), solifenacin (5-10mg daily), tolterodine (2-4mg daily), and fesoterodine (4-8mg daily), but the choice of medication and dosage should be individualized based on patient factors such as age, renal function, and comorbidities.
• It is essential to monitor for side effects, including dry mouth, constipation, blurred vision, cognitive impairment, and urinary retention, and adjust the treatment plan accordingly.
• Anticholinergics are contraindicated in narrow-angle glaucoma, severe gastric retention, and myasthenia gravis, and alternative options like beta-3 agonists (mirabegron 25-50mg daily) should be considered in patients with contraindications or who cannot tolerate anticholinergic side effects 1.
• Regular follow-up is necessary to assess treatment efficacy and monitor for adverse effects, particularly urinary retention, and to adjust the treatment plan as needed. The use of antimuscarinic medications in men with a PVR volume of >150 ml is not recommended due to the increased risk of urinary retention 1.

From the FDA Drug Label

Although no dose adjustment is recommended with solifenacin succinate or tamsulosin based on the lack of pharmacokinetic interaction, mirabegron should be administered with caution to patients taking muscarinic antagonist medications for the treatment of OAB and in patients with clinically significant BOO because of the risk of urinary retention [see Warnings and Precautions (5. 2)].

When considering adding anticholinergic medication for Overactive Bladder (OAB) in males, it is essential to exercise caution due to the potential risk of urinary retention, especially in patients with clinically significant Bladder Outlet Obstruction (BOO).

• Key considerations include:
  • The potential for increased risk of urinary retention when combining mirabegron with muscarinic antagonist medications.
  • The need for careful monitoring and potential dose adjustment when co-administering mirabegron with other medications, particularly those with a narrow therapeutic index.
  • The importance of evaluating the patient's overall clinical profile and medical history before initiating combination therapy 2.

From the Research

Considerations Before Adding Anticholinergic for OAB in Males

• The choice of anticholinergic therapy should be guided by individual patient comorbidities, as objective efficacy of anticholinergic drugs is similar 3
• Care providers need to be well acquainted with the side effects of anticholinergics and select therapy based on individual patient parameters 3
• Anticholinergic burden and potential for drug-drug interactions, notably related to cytochrome P450 (CYP) 2D6, should be considered 4
• The use of anticholinergic medications among patients with OAB was associated with an increased risk of new-onset dementia compared to beta-3 agonist users 5
• Transdermally delivered oxybutynin was clearly the best treatment for dry mouth but was still worse than placebo 6

Patient Factors to Consider

• Age: men and those aged ≤75 years on anticholinergics had the highest risk of dementia relative to similar beta-3 agonist users 5
• Comorbidities: adults with OAB typically have a greater number of comorbid conditions, such as hypertension, depression, and dementia, compared with adults without OAB 4
• Cognitive function: trospium is an adequate anticholinergic choice for overactive bladder syndrome patients with pre-existing cognitive impairment 3
• Cardiac concerns: darifenacin is an adequate anticholinergic choice for overactive bladder syndrome patients with pre-existing cardiac concerns 3

Treatment Options

• Oral oxybutynin, immediate and extended release, as well as transdermal oxybutynin, may be offered as treatment for overactive bladder syndrome 3
• Tolterodine, immediate and extended release, may be offered as treatment for overactive bladder syndrome 3
• Solifenacin may be offered as treatment for overactive bladder syndrome, as it is associated with significant objective clinical improvement at 12 weeks 3
• Darifenacin may be offered as treatment for overactive bladder syndrome, as it is associated with significant objective clinical improvement at 12 weeks 3