Although antimuscarinic treatment is indicated for overactive bladder, many patients discontinue it because of dry mouth. Of available antimuscarinics oxybutynin is associated with the highest dry mouth rate. We compared the safety and tolerability of 5 mg solifenacin vs 15 mg oxybutynin immediate release.
At 12 Canadian centers a total of 132 patients with overactive bladder symptoms (greater than 1 urgency episode per 24 hours, and 8 or greater micturitions per 24 hours) were randomized to 5 mg solifenacin once daily or 5 mg oxybutynin 3 times daily for 8 weeks. The primary end point was the incidence and severity of dry mouth reported after direct questioning. Efficacy end points (3-day diary documented changes in urgency, frequency, incontinence, nocturia and voided volume), and changes on the Patient Perception of Bladder Condition scale and the Overactive Bladder Questionnaire were evaluated secondarily.
Of patients on solifenacin vs oxybutynin immediate release 35% vs 83% reported dry mouth (p