Intradetrusor onabotulinumtoxinA injections are significantly more efficacious than oral oxybutynin for treatment of neurogenic detrusor overactivity: results of a randomized, controlled, 24-week trial

Objective: To prospectively compare the results of intradetrusor onabotulinumtoxinA injections and oral oxybutynin for urinary continence, urodynamic parameters and quality of life in patients with neurogenic detrusor overactivity due to spinal cord injury. Methods: Adult patients under intermittent catheterization were randomized 1:1 to receive one injection of onabotulinumtoxinA 300U or oxybutynin 5mg, per oris, three times/day. Primary study endpoint was change in urinary incontinence episodes/24 hours and secondary study endpoints were maximum cystometric capacity, maximum detrusor pressure, bladder compliance and quality of life before randomization and at week 24. Results: Sixty-eight patients participated in the trial. Significant improvements in urinary incontinence per 24 hours, all investigated urodynamic parameters and quality of life were observed in both groups. Compared with oral oxybutynin, onabotulinumtoxinA was significantly more efficacious for all parameters investigated. Non-response to treatment was higher for oral oxybutynin (23.5%) than onabotulinumtoxinA (11.8%). Dry mouth was the most common adverse in patients with oral oxybutynin (72%) and transient macroscopic hematuria in patients with onabotulinumtoxinA (28%). Only one patient with oral oxybutynin dropped out the study because of adverse effects. Conclusion: The comparison of the two study drugs showed that onabotulinumtoxinA was significantly more efficacious than oral oxybutynin with regard to continence, urodynamic parameters and quality of life.