Experience with imidafenacin in the management of overactive bladder disorder

Abstract

Overactive bladder (OAB) is a chronic syndrome defined by symptoms of urinary urgency with no underlying medical causes. First-line treatment of OAB comprises fluid intake advice and bladder training, supplemented by anticholinergic drugs if necessary. Owing to the chronic nature of OAB, the ideal anticholinergic treatment should have good long-term efficacy and tolerability. There are many anticholinergics available, although some of these are not specific for the bladder and can cause adverse effects such as dry mouth, constipation, blurred vision or cognitive impairment. Imidafenacin (a newer anticholinergic which has been marketed in Japan since 2007) was developed to improve the tolerability of anticholinergic therapy. This article summarizes the pharmacological properties, pharmacokinetics, clinical efficacy and tolerability of imidafenacin in the treatment of OAB. Data from key clinical studies of imidafenacin show that it has a fast onset of action and is effective for the treatment of OAB. It selectively binds to muscarinic receptors in the bladder and is associated with a good safety profile compared with other anticholinergics. The clinical efficacy, superior tolerability and adjustable dosing of imidafenacin make it a good anticholinergic for the treatment of OAB.

Cognitive Safety and Overall Tolerability of Imidafenacin in Clinical Use: A Long‐Term, Open‐Label, Post‐Marketing Surveillance Study

“…To confirm the efficacy of a particular drug, a study should determine whether the therapeutic agent is superior to a placebo and whether it is also not inferior to a pre‐existing drug. However, imidafenacin has already been reported to have significantly higher efficacy than placebos in both phase 2 and 3 trials,and these findings have been well‐reviewed …”

“…However, imidafenacin has already been reported to have significantly higher efficacy than placebos in both phase 2 and 3 trials, 4,5 and these findings have been well-reviewed. 27 -29…”

Muscarinic Receptor Binding of the Novel Radioligand, [3H]Imidafenacin in the Human Bladder and Parotid Gland

“…Since imidafenacin exhibited greater selectivity for the M 3 than M 2 subtype in CHO-K1 cells expressing human muscarinic receptors (4), the high affinity of [ 3 H]imidafenacin for muscarinic receptors in the human parotid gland reflects M 3 -subtype selectivity. In vivo functional and ex vivo muscarinic receptor binding experiments in rats (5,6) and clinical studies in humans (9,10) showed that imidafenacin selected the bladder over the exocrine gland. These in vivo results appear to contradict the M 3 -subtype selectivity observed in vitro, but in vivo bladder selectivity has been mainly attributed to the pharmacokinetic property of this agent (6).…”

“…Imidafenacin is known to be a well-tolerated agent in clinical settings and causes fewer adverse effects (7,8). Masumori (9), Takeuchi et al (10), and Maggiore et al (11) recently reviewed the long-term efficacy, safety, and tolerability of imidafenacin and reported a reduced incidence of severe adverse events such as dry mouth and constipation. In addition, imidafenacin can be used safely for a long period of time even by cognitively vulnerable elderly patients with the symptoms of OAB.…”

Muscarinic receptors mediate cold stress‐induced detrusor overactivity in type 2 diabetes mellitus rats

“…In the current study, we used type 2 diabetes mellitus rats as a model of cold stress‐exacerbated LUTS in diabetes patients. Muscarinic receptor antagonists are considered as the first‐line drug to treat OAB syndrome . We determined if the muscarinic receptor antagonist, imidafenacin, could inhibit the cold stress‐induced detrusor overactivity in non‐diabetic and diabetic rats.…”