Tolterodine: as effective but better tolerated than oxybutynin in Asian patients with symptoms of overactive bladder.

Background: This double-blind, multicenter study compared the efficacy and tolerability of tolterodine (Pharmacia, Los Angeles, USA) with that of oxybutynin (Alza, Palo Alto, USA) in Asian patients with overactive bladder.

Methods: Two-hundred-and-twenty-eight adults with overactive bladder symptoms were randomized to receive tolterodine 2 mg twice daily (bid) (n = 112) or oxybutynin 5 mg bid (n = 116). After 8 weeks' treatment, changes in micturition diary variables, patients' perception of treatment benefit, and tolerability endpoints were determined.

Results: The mean (+/- SD) number of micturitions/24 h decreased by 2.6 +/- 2.9 (-21%) with tolterodine and 1.8 +/- 4.2 (-15%) with oxybutynin (both P = 0.0001 vs baseline). The mean number of incontinence episodes/24 h decreased by 2.2 +/- 2.3 (-85%) in the tolterodine group and by 1.4 +/- 1.8 (-58%) in the oxybutynin group (both P = 0.0001 vs baseline). Patient perception of treatment benefit was over 70% in each treatment group. Adverse events were significantly lower in the tolterodine group compared with oxybutynin-treated patients (55% vs 82%; P = 0.001). Dry mouth was reported by significantly fewer patients on tolterodine, compared with oxybutynin (35% vs 63%; P = 0.001) and withdrawals due to adverse events were lower in the tolterodine group than with those treated with oxybutynin (10% vs 16%). There were no safety concerns.

Conclusions: Tolterodine 2 mg bid is equally or more effective than oxybutynin 5 mg bid in the treatment of Asian patients with overactive bladder, and shows significantly better tolerability. This may enhance compliance during long-term treatment.