Despite the great number of reports about the efficacy of oestrogens or antimuscarinics on OAB symptoms, so far no author has tried to investigate whether the concomitant administration of these two drugs, acting on two different pathophysiological mechanisms, could have a synergic effect reducing the rate of non-responders to treatment.

Inclusion Criteria:

• All post-menopausal women with symptoms of overactive bladder and urodynamically proven pure detrusor overactivity

Exclusion Criteria:

• concomitant urodynamic stress incontinence
• documented recurrent urinary tract infections
• previous antimuscarinic treatment
• previous pelvic surgery
• concomitant systemic HRT
• history of breast or endometrial cancer
• neurological disease
• clinical contraindications to treatment with oestrogen or antimuscarinics
• patients included in other ongoing clinical trials