Repeated botulinum toxin type A (Dysport®) injections for women with intractable detrusor overactivity: a prospective outcome study

Introduction and hypothesis We present the cohort of 33 women who underwent botulinum toxin type A (BTX-A) injections examining the efficacy and safety of BTX-A in idiopathic detrusor overactivity (IDO). The aim of this report is to describe the outcomes of those who underwent repeated injections of BTX-A. Methods All 33 women had 3 or more injections with an initial dose of 500 units of Dysport (R) with subsequent injections between 500 and 750 U, administered by the classic trigone-sparing flexible/rigid cystoscopic technique. An informed consent was obtained in all cases. Efficacy was measured using voiding diaries and quality of life (QOL) assessed with the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF). This project was approved by the Clinical Effectiveness Department and the Drugs and Therapeutics Committee (DTC). Therefore, ethical approval was not required. Results This study included 33 women who have been successfully treated with repeated intradetrusor injections of BTXA (Dysport (R)). Mean duration between the first and second injections was 15.2 +/- 7.2 months, whereas between the second and third was 19.2 +/- 10 months (P = 0.025). Two women developed urinary tract infection and required clean intermittent self-catheterization. Three women required dose escalation to 750 units. Longer duration of subjective QOL improvement was noted between the second and third botulinum toxin injections compared to duration between the first and second injections. Conclusions BTX-A appears to be effective and safe after repeated administration in women with IDO. The duration of the injection tends to get prolonged after the second injection.