The treatment of detrusor instability in post-menopausal women with oxybutynin chloride: a double blind placebo controlled study.

Idiopathic detrusor instability is a common cause of incontinence in the elderly for which anticholinergic agents are regularly prescribed. Oxybutynin chloride combines anticholinergic action with direct muscle relaxant properties. We performed a double blind placebo controlled fixed dose cross over study of oxybutynin chloride in post-menopausal women suffering from detrusor instability. We found oxybutynin chloride significantly more effective than placebo at reducing the symptoms of urgency and urge incontinence and more effective at reducing the height of the highest unstable detrusor contraction. This was at the expense of an increased residual urine and considerable side effects.