OAB occurs in approximately 50% to 75% of men with BPO and up to 38% of men with BPO continue
to suffer from OAB after relief the obstruction.Symptoms of OAB are more bothersome than the
voiding complaints of slow stream and hesitancy. However, the patients with both BPO and OAB
are often not treated with muscarinic receptor antagonists due to concern that they will
experience acute urinary retention.
Tolterodine is a potent and pure muscarinic receptor antagonist that was developed
specifically for the treatment of overactive bladder. Recently, studies revealed that
tolterodine was effective, safe and well tolerated in adults with OAB and urodynamically
confirmed BPO.However, the optimal dosage of antimuscarinic for the treatment of OAB
coexisting BPO was not yet fully assessed. In real clinical situation, some patients complain
voiding difficulty after addition of antimuscarinics and want to stop antimuscarinics.It is
probable that a lower dosage of antimuscarinics combined with alpha-adrenergic antagonists
can be used safely in OAB patients with BOO, with the same efficacy.
This study is designed to investigate the optimal doses of tolterodine SR in combination with
doxazosin in men with both BOO and OAB based on efficacy, safety, and tolerability.