TOLTERODINE

Tolterodine is a competitive muscarinic receptor antagonist which has recently been launched for the treatment of overactive bladder. Tolter odine shows functional selectivity for the bladder over the salivary g lands in vivo, which is not attributable to muscarinic receptor subtyp e selectivity. It is as potent as oxybutynin in inhibiting bladder con traction, but is much less potent in inhibiting salivation, suggesting that it may have less propensity to cause dry mouth in clinical use. In patients with overactive bladder, tolterodine significantly reduces the frequency of micturition and number of incontinence episodes, whi le increasing the average volume voided. The onset of pharmacological action of tolterodine is < 1 hour and therapeutic efficacy is maintain ed during long term treatment. In comparative trials, tolterodine and oxybutynin are equivalent in terms of efficacy. However, tolterodine i s significantly better tolerated than oxybutynin, particularly with re spect to the incidence and severity of dry mouth. No clinically releva nt ECG changes have been noted with tolterodine.