[Efficacy of repeat injections of botulinum A toxin to the detrusor in neurogenic bladder overactivity].

PURPOSE: Toxin injections are an effective treatment for neurogenic detrusor overactivity. The efficacy of repeat injections is not well documented. The objective of this study was to evaluate the efficacy of repeat injections of toxin A to the detrusor in patients with neurogenic overactive bladders.

MATERIALS AND METHODS: Patients who had received 300-UI injections of Botox(R) were retrospectively studied. The clinical data included continence, duration of the absence of incontinence, changes in anticholinergic dosage or pad use and patient satisfaction. Urodynamic data analyzed were maximal cystometric capacity, bladder contraction and detrusor pressure during contraction. Data were analyzed by Wilcoxon and Kruskal-Wallis tests. RESULTS-DISCUSSION: Data for 42 patients (30 men, 12 women) were analysed. Pathologic features were trauma to the spinal cord, multiple sclerosis or varied causes of myelopathy. Patients received 1 to 6 injections of Botox(R). The mean duration of efficacy was 6 months. Efficacy did not differ among successive injections. Anticholinergic drugs were discontinued in 43% of patients and pad use in 48%. A total of 80% of the patients were satisfied with the treatment. Bladder contraction disappeared in 70% of patients. The mean maximal cystometric capacity increase was 144 ml.

CONCLUSION: Clinical and urodynamic data show that repeat injection of toxins to the detrusor remains an effective therapy for neurogenic bladder overactivity. Efficacy for continence is maintained during successive injections.