Tolterodine and its active 5-hydroxymethyl metabolite: pure muscarinic receptor antagonists.

Tolterodine and its major active 5-hydroxymethyl metabolite (5-HM) are potent muscarinic receptor antagonists that show selectivity for the urinary bladder over salivary glands in vivo. This tissue selectivity cannot be attributed to muscarinic receptor subtype selectivity, since both compounds are non-selective with respect to the M1-M5 receptor subtypes. The aim of the present in vitro study was to determine the specificity of tolterodine and 5-HM for muscarinic receptors compared to other potential cellular targets.

Tolterodine: selectivity for the urinary bladder over the eye (as measured by visual accommodation) in healthy volunteers.

Objective: Tolterodine exhibits a favourable selectivity for the urinary bladder over salivary glands in vivo, in the anaesthetised cat, whereas oxybutynin shows the opposite selectivity profile in this model. This study further evaluated the selectivity profiles of tolterodine and oxybutynin by comparing the effects on bladder function and visual accommodation in the same individuals.

Methods: In a double-blind, randomised, four-way crossover study, 16 healthy volunteers received single oral doses of tolterodine 5 mg and oxybutynin 2.

Clinical experiences with tolterodine.

Tolterodine is the first muscarinic receptor antagonist that has been specifically developed for the treatment of overactive bladder. The objectives in the discovery program were to design a potent muscarinic receptor antagonist that is equipotent to oxybutynin in the bladder, but less potent in salivary glands, with the aim of improving tolerability (less dry mouth) in patients with overactive bladder. Tolterodine is non-selective with respect to the muscarinic M1-M5 receptor subtypes, but has a greater effect on the bladder than on salivary glands in vivo, in both animals and humans.

Tissue distribution of tolterodine, a muscarinic receptor antagonist, and transfer into fetus and milk in mice.

Tolterodine ((R)-N,N-diisopropyl-3-(2-hydroxy-5-methyl-phenyl)-3-phenylpropanamine, CAS 124937-51-5) is an antimuscarinic agent developed specifically for the treatment of the overactive bladder. In this study, the extent and profile of tissue distribution of 14C-tolterodine, after single and repeat oral dosing, was investigated in the mouse. Overall, distribution of radioactivity in tissues was rapid, and there were no gender-specific differences.

Pharmacological characterisation of the enantiomers of BM-5, a muscarinic partial agonist with opposed enantioselectivity between affinity and efficacy.

The interaction of (R) and (S) enantiomers of the chiral oxotremorine analogue BM-5 with muscarinic acetylcholine receptors was studied in vitro using radioligand binding and isolated tissue preparations. The in vivo effects of (R)-BM-5 were also studied in anaesthetised cat. No receptor or tissue selectivity was found for either enantiomer in radioligand binding studies in cells expressing human muscarinic receptors (M1-M5) or in guinea pig tissues.