darifenacin and Disease-Models--Animal

Anticholinergics are commonly used in primary and secondary care settings for the treatment of overactive bladder syndrome. The number of anticholinergic drugs available on the market is increasing and various studies, both observational and randomized controlled trials, have evaluated effectiveness of the different preparations available. When anticholinergic therapy is prescribed, there is still uncertainty about which anticholinergic drugs are most effective, at which dose, and by which route of administration. There is also uncertainty about the role of anticholinergic drugs in different patient groups, particularly in the elderly. The rationale for using anticholinergic drugs in the treatment of overactive bladder syndrome is to block the parasympathetic acetylcholine pathway and thus abolish or reduce the intensity of detrusor muscle contraction. There are currently five recognized subtypes of muscarinic receptor; the M1, M2, and M3 subtypes are of interest in bladder activity. Muscarinic receptors are found in other parts of the body, eg, in the gut, salivary glands, tear ducts. Side effects associated with non-selective antimuscarinics can be particularly distressing in the elderly. The development of bladder selective M3 specific antagonists has the advantage of providing increased efficacy with minimal side effects. Darifenacin is one such preparation. The aim of this review is to assess the pharmacology, interactions and the safety and tolerability of darifenacin in the treatment of overactive bladder in the elderly population with particular reference to clinical trial data available.

Topics: Aging; Animals; Behavior Therapy; Benzofurans; Cardiovascular System; Combined Modality Therapy; Disease Models, Animal; Drug Tolerance; Electrocardiography; Humans; Muscarinic Antagonists; Pyrrolidines; Rats; Salivation; Treatment Outcome; Urinary Bladder, Overactive; Urinary Incontinence

Overactive bladder associated with bladder outlet obstruction (BOO) is a highly prevalent condition, which is usually treated with antimuscarinics. However, the potential effects of antimuscarinics on the structure and function of bladder have not been investigated thus far.. Sprague-Dawley(R) rats accepted bladder neck obstruction surgery or sham surgery, and then received treatment of three different antimuscarinics (Solifenacin, Darifenacin, and Tolterodine) or vehicle. After 3, 6 and 12 weeks, the bladder function and structure were measured. The effect of antimuscarinics on cellular alteration in vitro was observed under mechanical stimulation. Bladder morphology were examined by immunohistochemistry, and the bladder function were investigated by cystometry and strip contractility test. The expression of muscarinic receptors and inflammatory cytokines were measured by PCR and Western blotting.. Here we demonstrate, both in vitro and in vivo, that antimuscarinics are protective regulators for the bladder structure and function. Antimuscarinics decrease the weight of bladders with BOO. Antimuscarinics improve the voiding parameter and enhance the contraction of bladder smooth muscle. The results also show that antimuscarinics inhibit the proliferation of bladder smooth muscle cells both in vivo and in vitro, it can reduce the collagen deposition and inflammatory cytokines in bladders with BOO. During this process, the expression of M2 and M3 receptors was altered by antimuscarinics.. Antimuscarinics could reverse the structural and functional changes of BOO bladder wall at cellular and tissue level, and the alteration of M2 and M3 receptors may be involved in this biological process.

Topics: Animals; Benzofurans; Cell Line; Cell Proliferation; Collagen; Cytokines; Disease Models, Animal; Female; Humans; Immunohistochemistry; Muscarinic Antagonists; Muscle Contraction; Myocytes, Smooth Muscle; Potassium Chloride; Proliferating Cell Nuclear Antigen; Protective Agents; Pyrrolidines; Rats; Rats, Sprague-Dawley; Receptor, Muscarinic M3; Tolterodine Tartrate; Urinary Bladder; Urinary Bladder Neck Obstruction

To clarify the basic mechanism involved in the pathophysiology of cystitis by characterizing the urodynamic parameters, pharmacologically relevant (muscarinic and purinergic) receptors, and the in vivo release of adenosine triphosphate (ATP) in the bladder of hydrochloric acid (HCl)-treated rats.. The muscarinic and purinergic receptors in rat tissue were measured by radioreceptor assays using (N-methyl-³H) scopolamine methyl chloride ([³H]NMS) and αβ-methylene-ATP (2,8-³H) tetrasodium salt ([³H]αβ-MeATP), respectively. The urodynamic parameters and ATP levels were measured using a cystometric method and the luciferin-luciferase assay, respectively.. In the HCl-treated rats, the micturition interval and micturition volume were significantly (48% and 55%, respectively, P <.05) decreased and the number of micturitions was significantly (3.2-fold, P <.05) increased compared with those of the control rats. The maximal number of binding sites for [³H]NMS and [³H]αβ-MeATP was significantly (55% and 72%, respectively, P <.001) decreased in the bladder of HCl-treated rats, suggesting downregulation of both muscarinic and purinergic receptors. In the HCl-treated rats, the inhibition constant, K(i), values for oxybutynin, solifenacin, and darifenacin were significantly (1.3-1.4-fold, P <.05) increased, but those for tolterodine and AF-DX116 were unchanged. Similarly, the inhibition constant for A-317491, pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid tetrasodium, and MRS2273 was significantly (5.5, 11, and 7.6-fold, respectively, P <.001) increased. Furthermore, the in vivo release of ATP was significantly (P <.05) enhanced in the HCl-treated rat bladder.. Both muscarinic and purinergic mechanisms might be, at least in part, associated with the urinary dysfunction due to cystitis.

Topics: Adenosine Triphosphate; Animals; Benzhydryl Compounds; Benzofurans; Cresols; Cystitis; Disease Models, Animal; Down-Regulation; Female; Hydrochloric Acid; Mandelic Acids; N-Methylscopolamine; Organophosphonates; Phenols; Phenylpropanolamine; Pirenzepine; Polycyclic Compounds; Pyridoxal Phosphate; Pyrrolidines; Quinuclidines; Radioligand Assay; Rats; Rats, Sprague-Dawley; Receptors, Muscarinic; Receptors, Purinergic; Solifenacin Succinate; Tetrahydroisoquinolines; Tolterodine Tartrate; Urinary Bladder; Urination; Urodynamics

The objective of the study was to evaluate the local effects of three antimuscarinics excreted into human urine after oral ingestion. Two normal adult collected their voided urine after taking oral doses of tolterodine, darifenacin, and solifenacin for 7 days with a 14-day washout period. The urodynamic effect of intravesically administered human urine on carbachol-induced bladder overactivity was studied in female rats. Cystometric parameters were measured during continuous infusion of saline and human urine and then a mixture of carbachol (30 microM) and human urine. Carbachol significantly reduced the intercontraction interval and bladder capacity in the control (urine taken in the absence of oral antimuscarinics) and tolterodine- or darifenacin-administered groups. However, human urine obtained after taking solifenacin prevented the carbachol-induced detrusor overactivity. Urine excreted after oral ingestion of solifenacin provides a localized pharmacological advantage for the treatment of the overactive bladder syndrome.

Topics: Administration, Oral; Animals; Benzhydryl Compounds; Benzofurans; Cresols; Disease Models, Animal; Female; Humans; Muscarinic Antagonists; Muscle, Smooth; Phenylpropanolamine; Pyrrolidines; Rats; Rats, Sprague-Dawley; Receptor, Muscarinic M3; Tolterodine Tartrate; Treatment Outcome; Urinary Bladder, Overactive; Urine

1 The M3 muscarinic receptor subtype is widely accepted as the receptor on smooth muscle cells that mediates cholinergic contraction of the normal urinary bladder and other smooth muscle tissues, however, we have found that the M2 receptor participates in contraction under certain abnormal conditions. The aim of this study was to determine the effects of various experimental pathologies on the muscarinic receptor subtype mediating urinary bladder contraction. 2 Experimental pathologies resulting in bladder hypertrophy (denervation and outlet obstruction) result in an up-regulation of bladder M2 receptors and a change in the receptor subtype mediating contraction from M3 towards M2. Preventing the denervation-induced bladder hypertrophy by urinary diversion prevents this shift in contractile phenotype indicating that hypertrophy is responsible as opposed to denervation per se. 3 The hypertrophy-induced increase in M2 receptor density and contractile response is accompanied by an increase in the tissue concentrations of mRNA coding for the M2 receptor subtype, however, M3 receptor protein density does not correlate with changes in M3 receptor tissue mRNA concentrations across different experimental pathologies. 4 This shift in contractile phenotype from M3 towards M2 subtype is also observed in aged male Sprague-Dawley rats but not females or either sex of the Fisher344 strain of rats. 5 Four repeated, sequential agonist concentration response curves also cause this shift in contractile phenotype in normal rat bladder strips in vitro, as evidenced by a decrease in the affinity of the M3 selective antagonist p-fluoro-hexahydro-sila-diphenidol (p-F-HHSiD). 6 A similar decrease in the contractile affinity of M3 selective antagonists (darifenacin and p-F-HHSiD) is also observed in bladder specimens from patients with neurogenic bladder as well as certain organ transplant donors. 7 It is concluded that although the M3 receptor subtype predominantly mediates contraction under normal circumstances, the M2 receptor subtype can take over a contractile role when the M3 subtype becomes inactivated by, for example, repeated agonist exposures or bladder hypertrophy. This finding has substantial implications for the clinical treatment of abnormal bladder contractions.

Topics: Age Factors; Animals; Benzofurans; Carbachol; Denervation; Disease Models, Animal; Electric Stimulation; Female; Gene Expression Regulation; Humans; Hypertrophy; Male; Muscarinic Agonists; Muscarinic Antagonists; Muscle Contraction; Muscle, Smooth; Piperidines; Pyrrolidines; Rats; Rats, Inbred F344; Rats, Sprague-Dawley; Receptor, Muscarinic M2; Receptor, Muscarinic M3; RNA, Messenger; Urinary Bladder; Urinary Bladder Neck Obstruction; Urinary Bladder, Neurogenic