The role of oxybutynin in spinal cord injured patients with indwelling catheters

Purpose: The long-term benefits of oral oxybutynin in spinal cord injured patients with indwelling catheters is unknown. We reviewed our experience with this population of men and present the results of our analysis. Materials and Methods: A total of 109 male spinal cord injured patients at the Houston Veterans Affairs Medical Center have been treated with chronic indwelling catheters (80 transurethral and 29 suprapubic). Thirty-eight patients (35%) were identified as using oxybutynin on a regular basis. These patients were compared to those not using oxybutynin with regard to urodynamic parameters and upper tract deterioration. Specifically examined were bladder compliance, bladder leak point pressure, vesicoureteral reflux, hydronephrosis, urolithiasis, febrile urinary tract infections and serum creatinine greater than 2 mg./dl. Results: The mean duration of indwelling catheter use was 11.9 years (12.4 without oxybutynin and 10.9 on oral oxybutynin). Of the 31 patients with normal compliance (greater than 20 ml./cm. water), 24 (77%) were using oxybutynin (p = 0.001). Bladder leak point pressures were abnormal (greater than 35 cm. water) in 5 of 32 patients (16%) on oxybutynin versus 34 of 60 (57%) without it (p <0.001). Hydronephrosis was present in 15 of 66 patients (23%) without oxybutynin versus 1 of 36 (3%) with oxybutynin (p = 0.009). Febrile urinary tract infections occurred in 4 of 35 patients (11%) versus 17 of 62 patients (27%) with or without oxybutynin, respectively (p = 0.077). No significant differences were found between the 2 groups with regard to reflux, renal scars, stones or elevated serum creatinine. Conclusions: It appears that regular use of oxybutynin may be beneficial in spinal cord injured patients who require chronic indwelling catheters for bladder management. Our analysis reveals that patients who take oxybutynin regularly have better bladder compliance, lower bladder leak point pressures and less hydronephrosis. Until a prospective, randomized trial reveals contradicting outcomes, empiric use of oxybutynin in all spinal cord injured patients requiring chronic indwelling catheters seems justified.