Gabapentin: A novel drug as add-on therapy in cases of refractory overactive bladder in children

ObjectiveTo determine the effectiveness of gabapentin as an add-on therapy in children presenting with overactive bladder (OAB) not responding to conventional anticholinergics.Materials and methodsChildren with refractory OAB were included prospectively from March 2009 to February 2010. The inclusion criterion was persistence of symptoms while on conventional anticholinergics for 6 months. Gabapentin was prescribed as an add-on therapy. The patients were followed 4 weekly with bladder diary and urodynamic study was repeated at 3 months.ResultsThere were 31 children, 26 of neurogenic OAB and 5 of non-neurogenic origin. Mean ± SD age was 8.5 ± 5.3 years. Data were analyzed in 30 patients as treatment was terminated in 1 due to adverse effects. Continence improved in 16 (53.3%) patients. Voiding volume improved from 175 ± 90 to 320 ± 110 ml (p < 0.03). Objective assessment of OAB symptom relief showed marked improvement (p < 0.05). Mean maximum cystometric bladder capacity improved from 210 ± 94 to 360 ± 110 ml (p < 0.02). The maximal detrusor contraction decreased from 75 ± 35 to 25 ± 15 cm H2O (p < 0.02). Fourteen patients (46.7%) failed to respond to gabapentin therapy. These patients had baseline maximum cystometric bladder capacity <60% for age and maximum detrusor contractions >50 cm of water (p < 0.03).ConclusionsGabapentin gives moderate results in children with OAB refractory to conventional anticholinergics. In general, the drug is well tolerated with fewer adverse effects.