Are oxybutynin and trospium efficacious in the treatment of detrusor overactivity in spinal cord injury patients?

Objectives: To evaluate the efficacy of anticholinergic agents in the treatment of neurogenic overactive bladder (NOAB) and neurogenic detrusor overactivity (NDO) in spinal cord injury (SCI) patients on clean intermittent catheterisation (CIC). Methods: Chronic suprasacral SCI patients on CIC presenting with at least one urinary leakage a day were included. Urodynamics and voiding diaries were performed at baseline and 1 month follow-up. In case of NDO at baseline, an anticholinergic drug was prescribed. Results: The 231 SCI patients presented with one to five urinary leakages per day (mean 2.1). Urodynamics showed NDO in all patients. A new anticholinergic treatment was started in all, either in monotherapy (134 patients) or in association with the existing anticholinergic drug (oxybutynin+trospium bitherapy, 97 patients). The mean maximum bladder capacity significantly increased from 225 to 441 ml, and the mean involuntary detrusor contractions (IDC) significantly decreased from 67 to 41cm H2O. Only 75 SCI patients (32%) were fully continent. However, 25 out of these 75 patients showed persistent NDO, with amplitudes of IDC above 40cm H2O in 12 patients. Incontinence was still found in 156 SCI patients (67%), with an average of 1,2 leakages a day. In 100 patients, amplitudes of IDC remained above 40 cm H2O. There was no statistical difference between patients on anticholinergic monotherapy or bitherapy at follow-up. Conclusion: Anticholinergic treatment is not always satisfactory in terms of control of NDO and rarely allows full continence. Urodynamic follow-up is mandatory in all patients, even in those showing clinical continence.