Astellas Pharma Canada has reported encouraging results from a Canadian study which showed that patients with overactive bladder treated with solifenacin reported significantly lower incidence and severity of dry mouth, an often intolerable anti-cholinergic side effect, than those treated with oxybutynin immediate-release. This was one of the key findings contained in the Vector study.
The Vector study compared the tolerability of solifenacin versus oxybutynin immediate-release (IR) for the treatment of overactive bladder (OAB). A secondary objective was to assess the efficacy of solifenacin versus oxybutynin IR for the treatment of OAB.
In this multi-centre, prospective, randomized, double-blind, double-dummy, eight-week study, solifenacin was associated with a superior tolerability profile compared to oxybutynin IR. Patients on solifenacin experienced a 48% lower incidence of dry mouth and a lower severity of dry mouth, of which 75% were mild, compared with patients taking oxybutynin IR (p=0.001), said Astellas.
The findings also revealed significantly fewer withdrawals due to dry mouth as well as fewer overall adverse events (p=0.009), and fewer treatment related adverse events (p=0.0093) compared to oxybutynin IR. Both solifenacin and oxybutynin IR improved OAB symptoms and patient-reported outcomes, the company added.
Sender Herschorn, professor and chair of the division of urology at the University of Toronto, said: Findings from the Vector study are very encouraging. The fact that some patients discontinue treatment for OAB because of intolerable side effects counters our best efforts to encourage them to seek treatment which could improve their quality of life. It is important for medical professionals, as well as the patients themselves, to be aware of treatment options to optimize the management of OAB.