<p>Tolterodine is a competitive, specific muscarinic receptor antagonist which exhibits a selectivity for the urinary bladder over salivary glands, which have been demonstrated in non clinical pharmacological in vivo studies. Tolterodine has a high specificity for muscarinic receptors. A major active metabolite (5-hydroxymethyl derivative) of tolterodine exhibits a pharmacological profile which is similar to that of the parent compound. In extensive metabolisers this metabolite contributes significantly to the therapeutic effect of tolterodine. The effect of treatment can be expected within 4 weeks.</p>