[In which patients is the oxybutynin-desmopressin combination therapy indicated?]

We assume that desmopressin decreases nocturnal urine output of the enuretic child. The aim of this study is to evaluate the efficacy of desmopressin plus oxybutynin and to define urodynamic pattern in children with bladder hyperactivity partially-responders to oxybutynin alone (in which nocturnal enuresis persists in spite of bladder stability).

48 enuretic patients with urodynamically confirmed bladder hyperactivity were enrolled in the prospective study. All patients were treated with oxybutynin, 0.3-05 mg/Kg/day orally, and bladder therapy, for six months. At the end of this period, patients with excellent response (cessation of nocturnal and diurnal symptoms) was designed as group I (28 children, 58%); patients with partial response (persistence of nocturnal enuresis) as group II (19 children, 40%); and patients non-responders as group III (1 patient, excluded because of no completion of treatment). After six months patients were assessed by standardized urodynamic study. Group II patients were treated with combined therapy, desmopressin-20 mcg/day-plus oxybutynin, for six months. Group I patients served as controls.

The differences between mean bladder accommodation and mean voiding pressure in patients with excellent response and partially response to oxybutynin were statistically significant. After combined therapy 18 of 19 patients (95%) of group II became group I.

The efficacy of desmopressin plus oxybutynin is confirmed in patients with low final accommodation (< 3 ml/cm H2O) and high voiding pressure (> 70 cm H2O). Combined therapy can be a good choice of treatment in children with bladder hyperactivity with partial response to oxybutynin alone.