Oxybutynin, desmopressin and enuresis

Purpose: A review of the scarce literature concerning oxybutynin treatment for nocturnal enuresis reveals that its success is greatest when enuresis i s combined with daytime incontinence. The renal and bladder related charact eristics of children with monosymptomatic enuresis responsive to oxybutynin were evaluated. Materials and Methods: Renal concentrating capacity and functional bladder capacity were compared between 55 dry children who served as controls, and children with monosymptomatic enuresis who responded to desmopressin only ( group 1, 27), oxybutynin only (group 2, 11), combination desmopressin and o xybutynin (group 3, 7) or were resistant to all treatment alternatives (gro up 4, 23). Results: Renal concentrating capacity was lowest in groups 1 and 3 (939 +/- 147 mOsm./kg. controls, 856 +/- 158 group 1, 1,073 +/- 71 group 2, 762 +/- 1.19 group 3 and 970 +/- 146 group 4; p < 0.01), whereas they had high uri nary output (15.4 +/- 73.4 ml./kg. per hour controls, 22.2 +/- 10.2 group 1 , 13.5 +/- 4.3 group 2, 21.5 +/- 11.2 group 3 and 15.0 +/- 6.9 group 4; p < 0.01). Forced functional bladder capacity of that expected for age was low est in groups 2 to 4. (107 +/- 43% controls, 88 +/- 43 group 1, 71 +/- 25 g roup 2, 68 +/- +/- 22 group 3 and 59 +/- 22 group 4; p < 0.01). Conclusions: Children responding to oxybutynin have small bladders and prob ably hyperactive detrusors, whereas those responding to desmopressin or who need both drugs to achieve dryness have polyuria.