Early investigational β3 adreno-receptor agonists for the management of the overactive bladder syndrome.

INTRODUCTION: Antimuscarinic drugs form the mainstay of medical treatment for Overactive bladder Syndrome (OAB). With a proven efficacy but poor tolerability, other treatment modalities have been sought. Recent concerns regarding cumulative anticholinergic load and risk of dementia have provided further impetus to find novel OAB treatments. β3-adrenoceptor (β3-AR) agonists improve OAB symptoms by relaxing bladder tissue. As such, the search is underway to develop β3-AR agonist drugs for the treatment of OAB.

AREAS COVERED: The authors discuss studies on the only approved β3-AR agonist, mirabegron, followed by reports on β3-AR agonists in development, namely ritobegron and solabegron. The authors also discuss the early investigations of novel and putative β3-AR agonist drugs which are being assessed for management of OAB, including aryloxypropanolamine, TRK-380, AJ-9677, BRL37344 and CL 316,243. These investigations have also highlighted alternative unexpected modes of β3-AR action.

EXPERT OPINION: There are a number of β3-ARs in the pipeline but it is uncertain which, if any, will come to market and aid in the management of OAB. A picture of a β3-AR dual action which was unknown previously is emerging. Overall, the authors believe that it is an exciting time for the pharmacological management of OAB with new drugs on the horizon which could potentially improve the patient's quality of life.