Comparative efficacy and safety of extended-release and instant-release tolterodine in children with neural tube defects having cystometric abnormalities

Abstract

Aim To evaluate the comparative efficacy and safety of extended-release (ER) and instant-release (IR) tolterodine preparations in a pediatric population with neural tube defects having cystometric abnormalities. Materials and methods Twenty-five patients with neural tube defects and a similar demographic profile underwent a routine hemogram, liver function tests, renal function tests, urine culture, X-ray lumbo-sacral spine, and renal and bladder ultrasound. Vesicoureteric reflux was diagnosed by micturating cystourethrogram under fluoroscopy. Dimercaptosuccinic acid renal scintigraphy was performed to study the presence or absence of renal scars. Patients were treated with tolterodine ER (Group I: 2 mg once daily for 21 days) and tolterodine IR (Group II: 2 mg twice daily for 21 day) in a cross-over study with a 10-day washout period between administrations. Evaluation was by subjective assessment, visual analog scale, urodynamic assessment and adverse drug reaction monitoring. Results There was ultrasound evidence of hydroureteronephrosis in 20% of the patients. One patient out of 25 had impaired renal function and eight patients had renal scarring on dimercaptosuccinic acid scans. Both forms of the drug increased the maximum cystometric bladder capacity, decreased detrusor leak pressures and increased compliance compared to pre-therapy levels ( P = 0.0001). Visual analog scale showed a significant clinical improvement with both ER and IR tolterodine. A significant increase in maximum bladder capacity in the group receiving IR tolterodine as compared to the ER preparation was noted ( P = 0.0001). The decrease in detrusor leak pressures and improvement in compliance were not significantly different between the groups. No adverse effects of hyperpyrexia, flushing or intolerance to outdoor temperatures, or dryness of mouth were observed in either group. No patient suffered from constipation. Conclusion ER tolterodine 2 mg once daily is as effective and well tolerated in children with neurogenic bladder as IR tolterodine 2 mg twice a day. The latter was found to be more effective in terms of urodynamic parameters. ER formulation of tolterodine is less expensive and has the advantage of single dosage.