Combining imidafenacin with an alpha-blocker may effectively treat overactive bladder (OAB) symptoms in men with benign prostatic hyperplasia (BPH), according to new research.

In 4 double-blind randomized controlled trials of patients with BPH, a total of 389 men received an alpha-blocker along with imidafenacin, a selective antimuscarinic drug, and 390 men received an alpha-blocker alone (tamsulosin, alfuzosin, naftopidil, or silodosin) for up to 12 weeks.

According to a meta-analysis, OAB Symptom Score (OABSS) significantly improved by -1.88 with the combination compared with an alpha-blocker alone, “suggesting that alpha-blocker and imidafenacin treatment was effective in treating men with OAB,” Tong Cai, MD, of Qingdao University, Yantai in Shandong, China, and colleagues reported in the International Neurourology Journal. In addition, the total International Prostate Symptom Score (IPSS), the IPSS storage symptom score, the IPSS voiding symptom score, and the IPSS quality of life score all nonsignificantly improved by a mean difference of -0.77, -0.99, -0.34, and -1.49, respectively, with the combination vs monotherapy.

With respect to tolerability, postvoid residual volume significantly improved by a mean difference of 6.88 with imidafenacin plus the alpha-blocker compared with monotherapy. Maximum flow rate did not differ significantly between groups, however.


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Safety results showed no urinary retention or diminished cognitive function with imidafenacin at a dose of 0.1 or 0.2 mg twice a day. The antimuscarinic has low selectivity for salivary gland tissues so it may cause less dry mouth. Imidafenacin has a shorter half-life (2.9 hours) and lower accumulation than other anticholinergic drugs.

Dr Cai’s team noted that “many clinicians are hesitant to use anticholinergics in clinical practice because they may exacerbate the symptoms of OAB, particularly in patients with possible BPH … These results demonstrate that for men with OAB, imidafenacin add-on treatment with an alpha-blocker was safe.”

Reference

Cai T, Wang N, Liang L, Zhou Z, Zhang Y, Cui Y. Meta-analysis of the efficacy and safety of imidafenacin for overactive bladder induced by benign prostatic hyperplasia in men receiving alpha-blocker therapy. Int Neurourol J. 2020;24(4):365-374. doi:10.5213/inj.2040146.073