Objectives: To assess the cognitive effects of single doses of solifenacin 10 mg compared with placebo (primary objective) and oxybutynin immediate release (IR) 10 mg (secondary objective) in elderly subjects.
Methods: Single-centre, randomised, double-blind, placebo-controlled study in 12 healthy elderly volunteers, with three crossover periods separated by two 14-day washout periods. Each sequence consisted of a single dose of solifenacin 10 mg in one period, oxybutynin IR 10 mg in another and placebo in another. Aspects of attention, information processing, working memory, episodic memory and self-rated mood and alertness were tested using the validated Cognitive Drug Research computerised assessment system.
Results: There was no evidence from absolute mean values or changes from baseline to suggest that solifenacin 10 mg impaired cognition or self-ratings of mood and alertness versus placebo. Post-hoc ANCOVA showed no statistically significant cognitive deterioration with solifenacin versus placebo, when measured at a time point closest to the probable C(max) of solifenacin. Oxybutynin was associated with statistically significant impairments in several measures of cognitive function at a time point corresponding with its probable C(max).
Conclusion: In this pilot study, single 10 mg doses of solifenacin did not show any clear propensity to impair cognitive function in a healthy elderly population.