General Information

Ditropan XL (oxybutynin chloride) is a muscarinic antagonist.

Ditropan XL is specifically indicated for the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency, and frequency. Ditropan XL is also indicated for the treatment of pediatric patients aged 6 years and older with symptoms of detrusor overactivity associated with a neurological condition.

Ditropan XL is supplied as a 5 mg or 10 mg tablet for oral administration. The tablets must be swallowed whole with the aid of liquids, and must not be chewed, divided, or crushed. Ditropan XL may be administered with or without food. The recommended dosing is as follows:

Adults: The recommended starting dose of Ditropan XL is 5 or 10 mg once daily at approximately the same time each day. Dosage may be adjusted in 5-mg increments to achieve a balance of efficacy and tolerability (up to a maximum of 30 mg/day). In general, dosage adjustment may proceed at approximately weekly intervals.

Pediatric Patients Aged 6 Years of Age and Older: The recommended starting dose of Ditropan XL is 5 mg once daily at approximately the same time each day. Dosage may be adjusted in 5-mg increments to achieve a balance of efficacy and tolerability (up to a maximum of 20 mg/day).

Mechanism of Action

Ditropan XL (oxybutynin chloride) is a muscarinic antagonist. Oxybutynin relaxes bladder smooth muscle. Oxybutynin chloride exerts a direct antispasmodic effect on smooth muscle and inhibits the muscarinic action of acetylcholine on smooth muscle. No blocking effects occur at skeletal neuromuscular junctions or autonomic ganglia (antinicotinic effects).

Clinical Trial Results

Ditropan XL was evaluated for the treatment of patients with overactive bladder with symptoms of urge urinary incontinence, urgency, and frequency in three controlled studies and one open label study. The majority of patients were Caucasian (89.0%) and female (91.9%) with a mean age of 59 years (range, 18 to 98 years). Entry criteria required that patients have the urge or mixed incontinence (with a predominance of urge) as evidenced by > 6 urge incontinence episodes per week and >10 micturitions per day. Study 1 was a forced dose escalation design, whereas the other studies used a dose adjustment design in which each patient’s final dose was adjusted to a balance between improvement of incontinence symptoms and tolerability of side effects. Controlled studies included patients known to be responsive to oxybutynin or other anticholinergic medications, and these patients were maintained on a final dose for up to 2 weeks. The difference between Ditropan XL and placebo on the number of urge urinary incontinence episodes per week was statistically significant in ways comparable to oxybutynin.

The safety and efficacy of Ditropan XL in pediatrics were studied in 60 children in a 24-week, open-label, non-randomized trial. Patients were aged 6 to 15 years, all had symptoms of detrusor overactivity in association with a neurological condition (e.g., spina bifida), all used clean intermittent catheterization, and all were current users of oxybutynin chloride. Study results demonstrated that administration of Ditropan XL 5 to 20 mg/day was associated with an increase from baseline in mean urine volume per catheterization from 108 mL to 136 mL, an increase from baseline in mean urine volume after morning awakening from 148 mL to 189 mL, and an increase from baseline in the mean percentage of catheterizations without a leaking episode from 34% to 51%.

Urodynamic results were consistent with clinical results. Administration of Ditropan XL resulted in an increase from baseline in mean maximum cystometric capacity from 185 mL to 254 mL, a decrease from baseline in mean detrusor pressure at maximum cystometric capacity from 44 cm H2O to 33 cm H2O, and a reduction in the percentage of patients demonstrating uninhibited detrusor contractions (of at least 15 cm H O) from 60% to 28%.