Urgency in overactive bladder: translating experimental data into clinical practice

In overactive bladder (OAB) syndrome, urgency is considered to be the key symptom that generates or affects all other symptoms. Urgency has been defined by the latest International Continence Society (ICS) terminology report as "the complaint of a sudden compelling desire to pass urine, which is difficult to defer". This definition has caused some debate and a final terminology has not yet been agreed upon. However, many would agree that urgency is different from urge when describing bladder sensation, and "urgency" has become one of the leading topics in OAB diagnosis and a primary endpoint in evaluation of treatment. Despite the many potential targets for pharmacological treatment, few drugs other than antimuscarinic agents have passed the proof-of-concept stage. There are multiple mechanisms, some proven in concept but more theoretical, by which a pharmacological agent may facilitate lower urinary tract filling/urine storage, bladder sensation and bladder emptying, although organ selectivity is often a problem. Oxybutynin, tolterodine, darifenacin, solifenacin and trospium have shown superiority to placebo, with a different incidence of side effects among the different drugs. Larger randomized, controlled trials in clinical settings are required to further establish the role of these medications in the management of urgency and OAB syndrome.