Doxazosin Versus Tizanidine for Treatment of Dysfunctional Voiding in Children: A Prospective Randomized Open-labeled Trial

ObjectiveTo examine the efficacy and tolerability of tizanidine for the treatment of dysfunctional voiding in children compared with those of doxazosin.MethodsA total of 40 children with dysfunctional voiding were enrolled in a prospective, randomized, 2-parallel group, flexible-dose study. The evaluations were performed in accordance with the International Children's Continence Society guidelines. The children were followed up after 1 week and then monthly for 6 months for the clinical, urine culture, and urodynamic parameters. The degree of improvement was assessed using a satisfaction scale that ranged from 0 (no improvement at all) to 10 (total improvement).ResultsA total of 40 patients with a mean ± SD age of 7 ± 2.6 years were enrolled. The clinical and urodynamic parameters were comparable between both groups. At the last follow-up visit, both groups had had similar improvement in the severity of symptoms, satisfaction scale, and noninvasive flowmetry parameters. In the doxazosin group, urge episodes was the only symptom that showed a significant reduction compared with the baseline values (P = .028). However, the incidence of nocturnal enuresis, urgency attacks, and daytime incontinence were significantly reduced compared with baseline in the tizanidine group (P = .003, P = .008, and P = .017, respectively). Adverse effects were recorded in 6 patients (15%). Epigasteric pain was reported in 2 children (10%) who received doxazosin. In the tizanidine group, a loss of appetite was noted in 2 children (10%), epigastric pain in 1 (5%), and headache in 1 (5%).ConclusionTizanidine could be a safe and effective treatment of children with dysfunctional voiding due to pelvic floor/skeletal sphincter dysfunction. More placebo-controlled trails with larger sample sizes are needed.