Inhibitory effects of the ATP-sensitive potassium channel openers cromakalim, pinacidil and minoxidil on the carbachol-response curve in porcine detrusor muscle

Drugs Currently Undergoing Preclinical or Clinical Trials for the Treatment of Overactive Bladder: A Review

Background

Overactive bladder (OAB) is a common clinical condition for which current drug treatment comprises drugs blocking the cholinergic nerve supply, or augmenting the adrenergic nerve supply, to the detrusor muscle of the urinary bladder. Current treatments have drawbacks, including lack of efficacy and the development of adverse effects in some patients. Hence, new and better drugs for treating OAB will be clinically useful.

Objective

This review is meant to provide information on drugs currently undergoing preclinical or clinical trials for the treatment of OAB published in journal articles or elsewhere.

Methods

The cited articles were retrieved from PubMed and Google Scholar from January 1, 1990, to December 31, 2021. The search terms used were contraction or contractility, detrusor, inhibition, isolated or in vitro, in vivo, overactive bladder, and relaxant effect or relaxation.

Results

There are 4 classes of new drugs under various stages of development for the treatment of OAB. These are drugs acting on the autonomic nerve supply to the detrusor muscle of the urinary bladder that include the anticholinergics tarafenacin and afacifenacin and the β₃ adrenoceptor agonists solabegron and ritobegron; drugs acting on ion channels in the detrusor muscle (eg, potassium channel openers and calcium channel blockers), drugs acting on cellular enzymes like phosphodiesterase-5 inhibitors and Rho kinase inhibitors, and drugs acting on miscellaneous targets (eg, pregabalin and trimetazidine).

Conclusions

Drugs currently used to treat OAB target only the cholinergic and adrenergic cellular signalling pathways. There are many other drugs under trial targeting other cellular pathways that may be useful for treating OAB. Their approval for clinical use might improve the treatment of patients with OAB. (Curr Ther Res Clin Exp. 2022; 83:XXX–XXX)

A Chinese Medicine Formula "Xian-Jia-Tang" for Treating Bladder Outlet Obstruction by Improving Urodynamics and Inhibiting Oxidative Stress through Potassium Channels

The aim of this study is to investigate efficacy of a traditional Chinese medicine formula (named Xian-Jia-Tang, XJT) on bladder outlet obstruction (BOO) in rats and explore its mechanisms. Total 80 BOO model rats were established and randomly divided into 4 groups: physiological saline, XJT, Cesium Chloride (CC), and XJT and CC groups. Meanwhile, 12 rats were used as normal control. Bladder weight and urodynamics were measured. Oxidative stress level and mRNA expressions of potassium channels gene were detected in detrusor. The mRNA and protein levels of hypoxia inducible factor-α (HIF-α) in detrusor were detected by RT-PCR and Western blot. BOO model rats showed significantly higher bladder weight and abnormal urodynamics. XJT significantly improved the abnormal urodynamics and inhibited the oxidative stress and changes of mRNA levels of potassium channels genes in detrusor of BOO model rats. Moreover, KATP and SK2/3 mRNA were overexpressed in BOO model rats treated by XJT. Besides, the significantly increased levels of HIF-α mRNA and protein were also inhibited by XJT. However, these inhibition effects of XJT were weakened by CC. XJT could effectively improve the urodynamics and inhibit the oxidative stress caused by hypoxia through suppressing the role of potassium channels in BOO model rats.