CYP3A4 and interstitial cystitis: Total urinary volume > 3 l/day Significant hepatic or renal disease UTI (symptomatic or recurrent) Interstitial cystitis, haematuria, or BOO Pregnancy, lactation, or failure by women of childbearing age to use reliable contraception Use of CYP3A4 inhibitors Non-surgical treatment for incontinence within 4 weeks of study Incontinence treatment within 2 weeks of study