although urotherapy , including lifestyle modifications , is recommended initially , antimuscarinic medication remains one of the most common forms of therapy for oab in children . although various antimuscarinic drugs have been introduced and are widely used with proven efficacy and stability in adult oab patients , not all antimuscarinic drugs are suitable for children . oxybutynin chloride is the only antimuscarinic drug licensed for use in pediatric patients by the food and drug administration in the united states . most clinicians have prescribed oxybutynin for pediatric oab patients . however , oxybutynin is now available in an extended - release tablet form , which is superior to the previous immediate - release tablet form but is still not recommended for infants and toddlers . propiverine , an antimuscarinic drug widely used in adult oab patients , is popular in pediatric patients as well because it can be easily ground into a powdered form . in practice , propiverine could be easily administered to oab children with better drug compliance . however , few clinical studies about the outcomes of propiverine in children with oab have been reported . in the present study , therefore , we evaluated the efficacy and safety of propiverine . children with oab who were treated with propiverine from october 2006 to february 2011 in samsung medical center were retrospectively reviewed . a detailed history , including a lower urinary tract symptom ( luts ) questionnaire , physical examination , and 3-day frequency volume chart , was obtained from each patient . only children who received the drug for at least 2 weeks and who had evaluable pre- and post - treatment frequency volume charts were included in this study . any children with neuropathic bladder , spinal dysraphism , anatomical abnormalities ( e.g. , posterior urethral valves or vesicoureteral reflux ) , or suspected urinary tract infections were excluded . the efficacy of propiverine was measured on the basis of improvement of oab symptoms ( frequency , urgency , and urge incontinence ) , change of voiding frequency , and maximum voided volume . the symptom improvement data after propiverine treatment were classified into the following three categories : nonresponse ( 0 to 49% decrease of symptoms ) , partial response ( 50 to 99% decrease of symptoms ) , and full response ( 100% decrease of symptoms ) . patients were divided into the non - urge incontinence ( non - ui ) and urge incontinence ( ui ) groups according to their symptom severity . the cumulative response rates by treatment duration were also compared between the two groups . to evaluate differences in treatment success between groups during the study period , 68 children ( 37 male , 31 female ) with a median age of 5.9 years ( range , 3.1 to 10.0 years ) satisfied the inclusion criteria . eighteen patients ( 26.5% ) had ui , 17 patients ( 25.0% ) experienced nocturnal enuresis , and 4 patients ( 5.9% ) had constipation at treatment entry . median voiding frequency was 14 times per day ( range , 8 to 72 times ) , and the median functional bladder capacity was 140 ml ( range , 30 to 300 ml ) . the median treatment duration was 7.5 weeks ( range , 2 to 66 weeks ) , and the propiverine dosage at the end of the treatment period was 10 mg for 25 children ( 36.8% ) and 20 mg for 43 children ( 63.2% ) ( table 1 ) . the median voiding frequency during the daytime decreased from 14.0 to 8.5 , and median functional bladder capacity changed from 140 to 150 ml ( fig . 1 ) . the overall response rate after propiverine treatment was 86.8% in all the children . the response rate was higher in the non - ui group ( 88.0% ) than in the ui group ( 83.3% ) , but the difference was not statistically significant ( p>0.05 ) ( fig . - ui children , the cumulative response rates were 36.0% , 54.0% , 68.0% , 74.0% , 76.0% , and 78.0% at 4 , 8 , 12 , 16 , 20 , and 24 weeks , respectively . the cumulative response rates in ui children were 11.1% , 33.3% , 44.4% , 50.0% , 50.0% , and 55.6% , respectively , during the same period ( fig . adverse effects were identified in only two patients ( 2.9% ) , and neither case was severe ( one case of dry mouth and one of constipation ) ( table 2 ) . the incidence of oab in school - aged children ranges from 17.8 to 26% [ 2 - 4 ] . in a recent study , the incidence of pediatric oab in south korea was 16.6% in children aged 5 to 13 years . the prevailing theory of pediatric oab is a delay in the acquisition of cortical inhibition over uninhibited detrusor contractions . in general , it is believed that the maturation period for cortical control of voiding function is between 3 and 5 years of age , and the completion period for fine - tuning of the detrusor muscle is about 8 years . the sites of maturational delay are thought to be the reticulospinal pathways of the spinal cord or the inhibitory center of the cerebral cortex . children with oab might have difficulty achieving the mature voiding patterns that are characteristic of adulthood . inflammatory processes in the bladder wall are also thought to be an etiology of pediatric oab . such inflammation can also irritate receptors in the submucosal and detrusor muscle layers and lead to luts . children with idiopathic oab are initially treated with urotherapy ; a nonsurgical , nonpharmacological treatment consisting of lower urinary tract rehabilitation using regular voiding with drinking and voiding charts , lifestyle changes , and some specific interventions such as physiotherapy , alarm therapy , and neurostimulation . when urotherapy fails , antimuscarinic drugs can be used . for adult oab patients , various antimuscarinic drugs such as oxybutynin , propiverine , tolterodine , trospium chloride , and solifenacin have been introduced and are widely used with proven efficacy and stability [ 10 - 14 ] . in contrast , oxybutynin chloride is the only fda - approved antimuscarinic drug licensed for use in pediatric patients . currently , oxybutynin extended release ( er ) rather than oxybutynin immediate release ( ir ) is widely administered in south korea . oxybutynin er is superior to oxybutynin ir with regard to adverse effects ; however , it is only available in tablet form , which is difficult for infants and toddlers to swallow . oab children might show better drug compliance when treated with propiverine hydrochloride than oxybutynin because propiverine can be easily ground into a powdered form , whereas oxybutynin er tablets can not be broken . in addition , a previous comparative study of propiverine and oxybutynin in children revealed lower adverse drug reaction rates for propiverine than oxybutynin . therefore , it is very important that clinicians understand the efficacy and safety of this drug , which inevitably could be used in clinical practice . our study is meaningful because it is the first report of the efficacy and safety of propiverine in east asian children . recently , a randomized placebo - controlled clinical trial reported objective efficacy and good tolerability of propiverine . although that study was a well - designed randomized controlled study , it did not cover the differences in clinical outcomes according to the symptom severity of the oab children . we found that propiverine therapy leads to a significant increase in functional bladder capacity and a decrease in voiding frequency . the drug also dramatically improved luts in oab children ; the overall response rate was 86.8% for the total treatment group . a previous study reported the overall efficacy of propiverine in oab children to be 86.8% , and we found similar results in our study . antimuscarinic agents cause parallel shifts to the right of the concentration - response curves to acetylcholine . in addition to this antagonistic muscarinic effect , which it shares with other antimuscarinic agents , propiverine causes a concentration - dependent inhibition of the kcl- and cacl2-induced contractions . clinical practitioners have often encountered the problem of how long to prescribe anticholinergic drugs . according to our results , treatment should last for at least 8 weeks to achieve a response rate of 50% . for children with ui , the response rate after 8 weeks of treatment was 54.0% for the non - ui group , 33.3% for the ui group , and 48.5% for the overall treatment group . to the best of our knowledge , this study was the first to evaluate the cumulative response rate of propiverine for oab children without ui ; it is also the first study that compared non - ui and ui groups . we believe that our results will provide advantageous information about propiverine for pediatric use in clinical practice . adverse effects were reported in only two patients , and neither case experienced severe symptoms . this finding supports previous clinical reports that children experience adverse effects ( such as dry mouth or visual disturbances ) less frequently than do adults when treated with propiverine . our data showed lower adverse events than did previous studies that reported adverse effect rates after anticholinergics treatment in oab children [ 15 - 19 ] . propiverine might act specifically on the bladder in children ; therefore , extravesical adverse effects are minimal . the other hypothesis is that children can not easily express the symptoms of adverse reactions ; thus , these might be underreported . first , it was an uncontrolled retrospective study , and we evaluated the efficacy of therapy by using frequency volume charts and subjectively described improvements alone . the potential for bias also existed in the patient selection because we included only children with relatively good drug compliance . the second limitation of our study was that most of our patients received medication therapy not by itself but combined with standard urotherapy . the improvement in oab symptoms might be partially a result of the standard urotherapy . despite these limitations , however , our study results contain important and practical information for antimuscarinic drug treatment , especially propiverine , in children with oab . propiverine has good efficacy and is well tolerated as a treatment for children suffering from oab with or without ui . at least 9 weeks of treatment are needed to achieve a response rate of 50% . for children with ui ,
purposeantimuscarinic therapy remains one of the most common forms of therapy for overactive bladder ( oab ) in children . 
 however , few clinical studies on the outcomes of antimuscarinics in children with oab have been published . 
 therefore , we evaluated the efficacy and safety of propiverine , which is frequently prescribed for the treatment of pediatric oab.materials and methodswe retrospectively reviewed children with oab treated with propiverine within the past 5 years . 
 the response rates were compared between the non - urge incontinence ( non - ui ) and urge incontinence ( ui groups ) . 
 the cumulative response rate by treatment duration was also compared between the two groups.resultsamong a total of 68 children , 50 children ( 73.5% ) experienced ui . 
 the overall response rate was 86.8% . 
 functional bladder capacity after treatment was 150 ml , which represented an increase compared with the value ( 140 ml ) before treatment . 
 the voiding frequency per day decreased from 14.0 to 8.5 times . 
 the overall response rate ( 88.0% ) in the non - ui group was not significantly different from that seen in the ui group ( 83.3% ; p>0.05 ) . in non - ui children , the cumulative response rates were 36.0% , 54.0% , 68.0% , 74.0% , 76.0% , and 78.0% at 4 , 8 , 12 , 16 , 20 , and 24 weeks , respectively . 
 the cumulative response rates in the ui children were 11.1% , 33.3% , 44.4% , 50.0% , 50.0% , and 55.6% , respectively during the same respective time periods . 
 adverse effects were identified in only two ( 2.9% ) patients , and neither case was severe.conclusionspropiverine is effective and well tolerated as a treatment for children suffering from oab with or without ui .