Beyond Antimuscarinics: A Review of Pharmacological and Interventional Options for Overactive Bladder Management in Men.

CONTEXT

The role of overactive bladder (OAB) treatment in women beyond antimuscarinics has been evaluated extensively. Beta-3 agonists, botulinum toxin-A (BTX-A), and nerve stimulation are indicated in these patients. However, data on male patients in this clinical scenario are scarce.

OBJECTIVE

The aim of this systematic review was to evaluate the evidence on treatment options beyond antimuscarinics in men with OAB.

EVIDENCE ACQUISITION

A search of PubMed, EMBASE, Scopus, Web of science, Cochrane Central Register of Controlled Trials, and Cochrane Central Database of Systematic Reviews databases was performed for relevant articles published between January 2000 and October 2020, using the following Medical Subject Headings: "male/man," "LUTS," "overactive bladder," "storage symptoms," "urgency," "nocturia," "incontinence," "beta-3 agonist," "PDE-5 inhibitors," "botulinum toxin," "sacral nerve stimulation/neurostimulation," "percutaneous/transcutaneous tibial nerve stimulation," "PTENS," and "combination therapy." Evidence acquisition was performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. PROSPERO registration number is CRD42020201223.

EVIDENCE SYNTHESIS

Overall, 24 studies were retrieved. In male OAB, mirabegron (MIRA) is the most intensively investigated pharmacological option. A pooled analysis of five randomized clinical trials (RCTs), including 1187 patients, concluded that MIRA 50 mg was associated with a greater reduction in frequency versus placebo (-0.37, 95% confidence interval [CI]: -0.74, -0.01, p <  0.05). A pooled analysis of three RCTs, including 1317 male patients, has also shown that the addition of MIRA 50 mg in men receiving the α-blocker tamsulosin improved the mean number of micturitions per day (-0.27, 95% CI: -0.46 to -0.09, p <  0.05), urgency episodes (-0.50, 95% CI: -0.77 to -0.22, p <  0.05), total OAB symptom score (-0.66, 95% CI: -1.00 to -0.38, p <  0.05), and mean volume voided (+10.76 ml, 95% CI: 4.87-16.64, p <  0.05). MIRA treatment is well tolerated in men. Other pharmacological treatment options, such as phosphodiesterase-5 (PDE-5) inhibitors, should be considered investigational. BTX-A seems to be effective as third-line treatment in male OAB patients. A higher rate of intermittent self-catheterization (5-42%) is observed in male than in female patients. Data on nerve stimulation are scarce.

CONCLUSIONS

MIRA has the most robust data in terms of safety and efficacy in this patient population. Preliminary data in men suggest that BTX-A is indicated as an interventional treatment. Evidence for PDE-5 inhibitors and nerve stimulation is too limited to provide recommendations. Future studies in this population should aim to better define the best treatment sequence and to identify predictors for treatment response and failure, to determine a therapeutic approach tailored to patients' characteristics.

PATIENT SUMMARY

Overactive bladder is highly prevalent in men. Mirabegron 50 mg is the treatment option supported by the highest level of evidence when antimuscarinics failed. Botulinum toxin A injections seems to be an effective treatment as interventional option. Roles of nerve stimulation and phosphodiesterase inhibitors in male OAB patients are still to be defined.