Stable Atropine Loaded Film As a Potential Ocular Delivery System For Treatment Of Myopia.

PURPOSE: The objective of the present study was to prepare stable and high bioavailability ocular atropine loaded films (ATR-films) as potential ocular drug delivery systems for the treatment of myopia. METHODS: ATR-films were prepared by the solvent casting method and the physical properties of films were evaluated including thickness, water content, light transparency, disintegration time, and mechanical properties. FT-IR, DSC, XRD, TGA, AFM, and Raman spectroscopy were performed to characterize the film. The stability test was conducted under different conditions, such as high humidity, high temperature, and strong light. The pharmacokinetic study and irritation assessment were conducted in rabbits. The efficacy of ATR-films was evaluated by refraction and ocular biometry in myopia guinea pigs. RESULT: After optimizing the formulation, the resulting ATR-film was flexible and transparent with lower water content (8.43% ± 1.25). As expected, the ATR-film was stable and hydrolysate was not detected, while the content of hydrolysate in ATR eye drops can reach up to 8.1867% (limit: < 0.2%) in the stability study. The safety assessment both in vitro and in vivo confirmed that the ATR-film was biocompatible. Moreover, the bioavailability (conjunctiva 3.21-fold, cornea 2.87-fold, retina 1.35-fold, sclera 2.05-fold) was greatly improved compared with the ATR eye drops in vivo pharmacokinetic study. The pharmacodynamic study results showed that the ATR-film can slow the progress of form-deprivation myopia (~ 100 ± 0.81D), indicating that it has a certain therapeutic effect on form-deprivation myopia. CONCLUSION: The ATR-film with good stability and high bioavailability will have great potential for the treatment of myopia.

Evaluating revefenacin as a therapeutic option for chronic obstructive pulmonary disease.

INTRODUCTION: In chronic obstructive pulmonary disease (COPD), inhaled long-acting antimuscarinic agents (LAMA) are effective maintenance therapies used across all severity stages of the disease. Most of them are administered via dry powder inhalers, but these devices require a potent inspiratory flow which cannot be effectively achieved by patients with advanced disease. In such patients, inhaled therapy via nebulization might be an option. AREAS COVERED: Revefenacin is a LAMA that was specifically formulated for once daily nebulization and which was authorized by the FDA as a maintenance therapy for COPD. In phase II and III clinical studies discussed in this review, revefenacin demonstrated its rapid onset of action and sustained effect on lung function on both a short- and long-term basis. EXPERT OPINION: Nebulized revefenacin with once daily use does not require any particular effort of administration and hence can be used by patients with severe airways obstruction or by those having milder cognitive deficits. Further studies are needed, however, to better document the long-term cardiovascular safety and its ability to reduce the exacerbation rate.

[Changing patterns of medication prescription for COPD patients in France. Impact of long-acting muscarinic antagonists' availability]. / Évolution des traitements de fond entre 2001 et 2012 chez les patients atteints de BPCO en France. Impact de la mise à disposition des anticholinergiques de longue durée d'action.

INTRODUCTION: We studied the pattern changes over time of medication prescriptions for COPD and their conformity with French and international recommendations using data from patients in the prospective French cohort "Initiatives BPCO". METHOD: Eight hundred and forty-six patients have been included during a first period from August, 2001 till May 2006 (n=425) and a second period from June, 2006 till June, 2012 (n=421). The pivotal date was based on the tiotropium availability in France. RESULTS: During period 1, we recruited older patients (average 65 vs 64 years), less often women (19 vs 26 %) and having less severe airflow obstruction (mean FEV1 48 vs 54 %). The ICS prescriptions decreased in mild COPD, but there was no change for inhaled long-acting beta-2 agonist (LABA) (68 %). The use of LABA+LAMA association without ICS increased from 0.9 to 7 %, but remained lower than the fixed LABA+ICS association (26 %), less often prescribed than the triple association LABA+ICS+LAMA (32.5 % in period 2). The use of long-acting bronchodilators increased from 68 to 80 % between both periods. Vaccinations and rehabilitation remained insufficiently prescribed. LAMA had been added but did not appear to replace other drugs.

Pharmacological methods for the preclinical assessment of therapeutics for OAB: an up-to-date review.

INTRODUCTION: Licenced oral pharmacotherapies for overactive bladder (OAB) act on muscarinic receptors or ß3-adrenoceptors. The search for new drugs to treat OAB that have novel mechanisms of action is very active, with the aim of discovering more effective and/or better tolerated agents. METHODS: A literature review of the most frequently used pharmacological methods for the preclinical assessment of new agents aimed at treating OAB, such as isolated organ technique, electrophysiological techniques, radioligand binding assay, and animal models, was carried out. Novel potential developments based on recent knowledge of urothelial and neural mechanisms are also discussed. RESULTS: The isolated organ technique, electrophysiological techniques, and the radioligand binding assay are very effective methods for the demonstration that a novel pharmacological target with a specific and high affinity binding site for a new drug is present in the bladder and its modulation regulates functions critical for the pathophysiology of OAB. Afterward, the new drug should be shown to be effective in animal models of OAB, although the translational value of these models is limited by a poor pathophysiological relationship with human OAB. Exciting novel perspectives focusing in particular on the theory of the mucosal-bladder network have recently opened new paths in the discovery and assessment of new therapeutics in this field. CONCLUSIONS: Available experimental models still play a central role in the appraisal of OAB therapeutics; however, their shortcomings and the paucity of very effective drugs indicate the need for new models that better reproduce the pathophysiological features of OAB. Some emerging lines of research show promise. A change of perspective in the future evaluation of putative drugs is required, especially in the light of the latest knowledge on the key role of the mucosal-bladder network and the brain-bladder neural pathways.

Inhaled Umeclidinium in COPD Patients: A Review and Meta-Analysis.

A number of new agents for the management of chronic obstructive pulmonary disease (COPD) are at different stages of development, including several inhaled long-acting antimuscarinics (LAMA). Long-acting bronchodilators are considered to be central to the management of COPD due to the evidence supporting their efficacy and safety. Umeclidinium, a LAMA, has recently been approved for the maintenance treatment of moderate to very severe COPD in a number of countries. This comprehensive review and pooled meta-analysis provides detailed information about the efficacy and safety of this agent. The pharmacokinetics and pharmacodynamics of umeclidinium observed in phase I and II studies support its once-daily administration. Umeclidinium is rapidly cleared from blood, and renal or hepatic impairment do not lead to significant changes in drug disposition. A pooled analysis of phase III and comparative studies of umeclidinium in patients with moderate to very severe COPD showed significant improvement in lung function measures, including trough forced expiratory volume in 1 s (FEV1), as well as in acute exacerbations of COPD, dyspnea, and quality of life. Adverse effects, including known anticholinergic effects, were uncommon with umeclidinium. Limited data suggest the efficacy of umeclidinium is similar to that of tiotropium. Umeclidinium is administered as a dry powder inhaler, provides adequate lung delivery in patients with moderate to very severe airflow obstruction, and appears to be easily used by patients. Umeclidinium provides a safe and effective option as an inhaled LAMA for the management of COPD.

Once-daily glycopyrronium bromide (Seebri Breezhaler(®)) for the treatment of chronic obstructive pulmonary disease (COPD).

INTRODUCTION: Long-acting bronchodilators are the mainstay of pharmacological therapy for patients with chronic obstructive pulmonary disease (COPD). The choice of optimal bronchodilator therapy for COPD is increasingly difficult for clinicians as new treatments are marketed. AREAS COVERED: Inhaled glycopyrronium bromide (Seebri Breezhaler®) is a well-tolerated long-acting anti-muscarinic agent (LAMA) with a fast onset of action. In patients with moderate to severe COPD, glycopyrronium bromide has clinically important effects on level of FEV1, use of relief medication, day-time dyspnea scores, and probably also on health status. Furthermore, glycopyrronium bromide also has beneficial effects on dynamic hyperinflation and, probably by that, exercise tolerance. Glycopyrronium bromide has been shown to reduce the rate of exacerbations in patients with moderate to severe COPD, although as a secondary outcome only. EXPERT OPINION: Once-daily inhaled glycopyrronium bromide has positive impact on important COPD outcomes, comparable to the effects of other marketed LAMAs. Once-daily administration may improve adherence, and glycopyrronium bromide has the potential for a role in the future management of COPD similar to that of other long-acting anti-muscarinic agents, including tiotropium. Studies of glycopyrronium bromide with exacerbation rate as the primary outcome of interest is needed.

Discovery of novel quaternary ammonium derivatives of (3R)-quinuclidinyl amides as potent and long acting muscarinic antagonists.

Novel quaternary ammonium derivatives of (3R)-quinuclidinyl amides have been identified as potent M3 muscarinic antagonists with a long duration of action in an in vivo model of bronchoconstriction. The synthesis, structure-activity relationships and biological evaluation of this series of compounds are reported.

Umeclidinium for treating COPD: an evaluation of pharmacologic properties, safety and clinical use.

INTRODUCTION: Umeclidinium (UMEC) is a long-acting inhaled antagonist of muscarinic cholinergic receptors. The FDA approved UMEC for maintenance treatment of chronic obstructive pulmonary disease (COPD) in 2013 and it became available for commercial use as a single agent in 2014. After tiotropium, this is the only other once daily LAMA available for COPD patients. AREAS COVERED: In this article, we have comprehensively reviewed the pharmacokinetic properties and analyzed the currently available randomized controlled trials on the efficacy and safety profile of UMEC. We have discussed the current clinical application of UMEC and its future implication. EXPERT OPINION: UMEC is the newer long-acting antimuscarinic agent (LAMA) that has demonstrated significant improvement in lung function and improved the quality of life in moderate-to-severe COPD patients. It is suitable for once daily dosing, has low anticholinergic side effects and is well tolerated. Overall, it is a safe, effective and convenient LAMA for maintenance therapy in COPD patients.

Pharmacologic characterization of GSK-961081 (TD-5959), a first-in-class inhaled bifunctional bronchodilator possessing muscarinic receptor antagonist and ß2-adrenoceptor agonist properties.

The objective of the present studies was to characterize the pharmacologic properties of GSK-961081 [TD-5959; (R)-1-(3-((2-chloro-4-(((2-hydroxy-2-(8-hydroxy-2-oxo-1,2-dihydroquinolin-5-yl)ethyl)amino)methyl)-5-methoxyphenyl)amino)-3-oxopropyl) piperidin-4-yl [1,1'-biphenyl]-2-ylcarbamate], a novel first-in-class inhaled bifunctional compound possessing both muscarinic antagonist (MA) and ß2-adrenoceptor agonist (BA) properties (MABA). In competition radioligand binding studies at human recombinant receptors, GSK-961081 displayed high affinity for hM2 (Ki = 1.4 nM), hM3 muscarinic receptors (Ki = 1.3 nM) and hß2-adrenoceptors (Ki = 3.7 nM). GSK-961081 behaved as a potent hß2-adrenoceptor agonist (EC50 = 0.29 nM for stimulation of cAMP levels) with 440- and 320-fold functional selectivity over hß1- and hß3-adrenoceptors, respectively. In guinea pig isolated tracheal tissues, GSK-961081 produced smooth muscle relaxation through MA (EC50 = 50.2 nM), BA (EC50=24.6 nM), and MABA (EC50 = 11 nM) mechanisms. In the guinea pig bronchoprotection assay, inhaled GSK-961081 produced potent, dose-dependent inhibition of bronchoconstrictor responses via MA (ED50 = 33.9 µg/ml), BA (ED50 = 14.1 µg/ml), and MABA (ED50 = 6.4 µg/ml) mechanisms. Significant bronchoprotective effects of GSK-961081 were evident in guinea pigs via MA, BA, and MABA mechanisms for up to 7 days after dosing. The lung selectivity index of GSK-961081 in guinea pigs was 55- to 110-fold greater than that of tiotropium with respect to systemic antimuscarinic antisialagogue effects and was 10-fold greater than that of salmeterol with respect to systemic ß2-adrenoceptor hypotensive effects. These preclinical findings studies suggest that GSK-961081 has the potential to be a promising next-generation inhaled lung-selective bronchodilator for the treatment of airway diseases, including chronic obstructive pulmonary disease.

Discovery, synthesis and characterization of a highly muscarinic acetylcholine receptor (mAChR)-selective M5-orthosteric antagonist, VU0488130 (ML381): a novel molecular probe.

Of the five G-protein-coupled muscarinic acetylcholine receptors (mAChRs; M1-M5), M5 is the least explored and understood due to a lack of mAChR subtype-selective ligands. We recently performed a high-throughput functional screen and identified a number of weak antagonist hits that are selective for the M5 receptor. Here, we report an iterative parallel synthesis and detailed molecular pharmacologic profiling effort that led to the discovery of the first highly selective, central nervous system (CNS)-penetrant M5-orthosteric antagonist, with sub-micromolar potency (hM5 IC50=450 nM, hM5 Ki=340 nM, M1-M4 IC50>30 µM), enantiospecific inhibition, and an acceptable drug metabolism and pharmacokinetics (DMPK) profile for in vitro and electrophysiology studies. This compound will be a powerful tool and molecular probe for the further investigation into the role of M5 in addiction and other diseases.

Evaluation of fesoterodine fumarate for the treatment of an overactive bladder.

INTRODUCTION: Fesoterodine fumarate is an approved drug for overactive bladder. The aim of this study is to review the preclinical and most up to date clinical data on fesoterodine, with a special emphasis on its unique pharmacokinetic features and its implications on safety and tolerability in various patient populations. AREAS COVERED: In this review, the authors extensively reviewed available literature via PubMed search regarding fesoterodine, covering its mechanism of action, pharmacodynamics and pharmacokinetics, clinical efficacy, safety, and tolerability. EXPERT OPINION: Fesoterodine is an anti-muscarinic agent with a unique pharmacokinetic profile. It is a prodrug that is rapidly metabolized to its active form by nonspecific plasma esterases. Its metabolism is independent of the cytochrome P450 enzyme system. This along with its dual excretion pathways and minimal central nervous system penetration leads to less variability in drug exposure and allowance of administration in those with mild to moderate renal and hepatic insufficiency and in the geriatric population.

Profile of glycopyrronium for once-daily treatment of moderate-to-severe COPD.

Bronchodilators are central in the symptomatic management of chronic obstructive pulmonary disease (COPD). Long-acting muscarinic antagonists (LAMAs) and long-acting ß(2)-agonists (LABAs) are the main classes of long-acting bronchodilators. To date, tiotropium is the only once-daily LAMA available for the treatment of COPD. Glycopyrronium is a novel LAMA, currently in development for COPD. Phase II studies have shown that glycopyrronium 50 µg once daily provides clinically significant 24-hour bronchodilation with a rapid onset of action, which is faster than that of tiotropium, and a favorable safety and tolerability profile. The Phase III GLycopyrronium bromide in COPD airWays (GLOW) program has now confirmed the long-term efficacy and tolerability of glycopyrronium 50 µg once daily. The three studies included in this program have further shown that the effect of glycopyrronium versus placebo is similar to that of tiotropium in reducing dyspnea and the risk of exacerbations, as well as improving lung function, exercise tolerance, and health status in patients with COPD. The safety profile of glycopyrronium is also similar to that of tiotropium in terms of overall incidence of adverse events and muscarinic side effects. Glycopyrronium could be an alternative choice to tiotropium, and like tiotropium, has the potential to be used as a monotherapy or combination therapy. Phase II studies have shown that a fixed-dose combination of glycopyrronium and the 24-hour LABA indacaterol, produces rapid and sustained bronchodilation compared with indacaterol monotherapy in patients with COPD. Phase III studies are currently ongoing to assess the long-term efficacy and safety of this combination.

Safety and efficacy of dual therapy with GSK233705 and salmeterol versus monotherapy with salmeterol, tiotropium, or placebo in a crossover pilot study in partially reversible COPD patients.

BACKGROUND: GSK233705 is an inhaled, long-acting muscarinic antagonist in development for the treatment of chronic obstructive pulmonary disease (COPD). This study was performed to see if the addition of GSK233705 to salmeterol would provide greater bronchodilation than salmeterol or tiotropium alone in COPD. METHODS: In an incomplete-block, three-period, crossover design, dually responsive patients received three of the following five treatments: GSK233705 20 µg plus salmeterol 50 µg twice-daily; GSK233705 50 µg plus salmeterol 50 µg twice-daily; salmeterol 50 µg or placebo, each twice-daily; and tiotropium 18 µg or placebo once-daily for 7 days. Each treatment period was separated by a 14-day washout. The primary efficacy endpoint was morning (trough) forced expiratory volume in 1 second (FEV(1)) on Day 8, following 7 days of treatment. Secondary endpoints included pulmonary function, plethysmography, pharmacokinetics of GSK233705 and salmeterol, adverse events (AEs), electrocardiograms (ECGs), vital signs, and laboratory parameters. RESULTS: A total of 47 patients were randomized. The mean % predicted normal postbronchodilator FEV(1) was 55% at screening. Compared with placebo (n = 24), the adjusted mean change from baseline in trough FEV(1) on Day 8 was 215 mL higher with GSK233705 20 µg + salmeterol (n = 23) and 203 mL higher with GSK233705 50 µg + salmeterol (n = 27), whereas with salmeterol (n = 27) and tiotropium (n = 28) the changes were 101 mL and 118 mL higher, respectively. The primary efficacy results were supported by the results from the other secondary lung function assessments. AEs were reported by similar proportions of patients across the treatment groups, with headache the most frequently reported treatment-related AE reported by one subject receiving each of GSK233705 20 µg + salmeterol, tiotropium, and placebo. No significant differences were seen in vital signs, ECGs, or laboratory parameters between the groups. CONCLUSION: The addition of GSK233705 to salmeterol in partially reversible COPD patients resulted in greater bronchodilation than salmeterol or tiotropium alone and was well tolerated.

The pharmacokinetic profile of fesoterodine 8 mg with daytime or nighttime dosing.

PURPOSE: Diurnal variation can affect drug pharmacokinetics. Fesoterodine is a new antimuscarinic drug for the treatment of overactive bladder (OAB). We estimated the relative bioavailability of 5-hydroxymethyl tolterodine (5-HMT), the active metabolite of fesoterodine, following nighttime and daytime administration. METHODS: In this randomized, open-label, two-period, two-treatment crossover, single-dose study, healthy subjects received daytime and nighttime oral dosing of fesoterodine 8-mg sustained-release tablets, separated by a minimum 60-h washout period. Blood samples for 5-HMT PK determination were collected before dosing and at specified intervals up to 48 h postdose. Safety was assessed by adverse event (AE) reports. RESULTS: Fourteen subjects completed the study. Plasma concentration versus time profiles (AUC) of 5-HMT were similar for daytime and nighttime dosing. Mean AUC(infinity) 5-HMT values were 47.9 and 51.4 ng h/mL for nighttime and daytime dosing, respectively; the mean time to reach maximum concentration (C(max)) values were 3.9 and 5.0 ng/mL, respectively. Nighttime versus daytime AUC(infinity) and C(max) ratios of 5-HMT were 93 and 79%, respectively; 90% confidence intervals (CIs) indicated equivalence for AUC(infinity) but not for C(max). The median time to reach maximum concentration (T(max)) was 5.0 h for both dosing regimens, and the mean terminal elimination half-life (T((1/2))) was 5.9 and 5.7 h for nighttime and daytime dosing, respectively. Seven treatment-related AEs, most commonly headache, occurred in five subjects. CONCLUSIONS: The AUC values for daytime and nighttime administration of fesoterodine were equivalent. The 21% reduction in the C(max) for nighttime dosing is unlikely to be clinically relevant. No safety issues were apparent. These results support both daytime and nighttime administration of fesoterodine for OAB treatment.

Evaluation of drug-drug interactions with fesoterodine.

PURPOSE: To assess drug-drug interactions of fesoterodine with cytochrome P450 (CYP) 3A4 inhibitor (ketoconazole), inducer (rifampicin), and substrates (ethinylestradiol and levonorgestrel). METHODS: Effects of ketoconazole 200 mg twice daily and rifampicin 600 mg twice daily on fesoterodine 8 mg once daily were investigated in CYP2D6 extensive metabolizers (EMs) and poor metabolizers (PMs) based on 5-hydroxymethyl tolterodine (5-HMT) pharmacokinetics (principal active fesoterodine metabolite and CYP3A4 substrate). Effects of fesoterodine 8 mg versus placebo once daily on ethinylestradiol and levonorgestrel were investigated based on oral contraceptive pharmacokinetics and on pharmacodynamic effects on progesterone, luteinizing hormone, follicle-stimulating hormone, and estradiol plasma levels. RESULTS: Compared with fesoterodine alone, coadministration of fesoterodine with ketoconazole resulted in increases in mean 5-HMT maximum concentration in plasma (C(max); from 3.0 to 6.0 ng/mL in EMs and from 6.4 to 13.4 ng/mL in PMs) and mean area under the plasma concentration time curve (AUC; from 38.2 to 88.3 ng h/mL in EMs and 88.3 to 217.2 ng h/mL in PMs). Coadministration of festerodine with rifampicin resulted in decreases in mean 5-HMT C(max) (from 5.2 to 1.5 ng/mL in EMs and from 6.8 to 1.9 ng/mL in PMs) and mean AUC (from 62.4 to 14.4 ng h/mL in EMs and from 87.8 to 19.6 ng h/mL in PMs). Fesoterodine did not affect oral contraceptive pharmacokinetics or pharmacodynamics or the suppression of ovulation. CONCLUSIONS: Fesoterodine dosage should not exceed 4 mg once daily when taken concomitantly with potent CYP3A4 inhibitors. Coadministration of CYP3A4 inducers with fesoterodine may produce subtherapeutic 5-HMT exposures. No dose adjustment is necessary for concomitant use of fesoterodine with oral contraceptives.

Predictive power of an in vitro system to assess drug interactions of an antimuscarinic medication: a comparison of in vitro and in vivo drug-drug interaction studies of trospium chloride with digoxin.

The authors studied a potential drug-drug interaction via findings from in vitro and in vivo studies, to assess whether the in vitro system was predictive of in vivo clinical pharmacokinetic outcomes. An in vitro experiment and a clinical study were performed to assess the potential for interaction. The effect of trospium chloride on human P-glycoprotein-mediated transport of [3H]-digoxin was determined in vitro. A randomized, crossover clinical trial in 40 subjects was performed to evaluate the effect of trospium on the pharmacokinetics of digoxin in vivo. The findings from the studies were then compared. The in vitro findings in this study were corroborated by the clinical study via assessment of inhibition and impact on pharmacokinetic parameters. The in vitro system for assessment of a potential interaction of 2 drugs excreted primarily through the kidney was predictive of the pharmacokinetic outcomes obtained from a clinical setting.

Pharmacokinetics and pharmacodynamics in clinical use of scopolamine.

The alkaloid L-(-)-scopolamine [L-(-)-hyoscine] competitively inhibits muscarinic receptors for acetylcholine and acts as a nonselective muscarinic antagonist, producing both peripheral antimuscarinic properties and central sedative, antiemetic, and amnestic effects. The parasympatholytic scopolamine, structurally very similar to atropine (racemate of hyoscyamine), is used in conditions requiring decreased parasympathetic activity, primarily for its effect on the eye, gastrointestinal tract, heart, and salivary and bronchial secretion glands, and in special circumstances for a CNS action. Therefore, scopolamine is most suitable for premedication before anesthesia and for antiemetic effects. This alkaloid is the most effective single agent to prevent motion sickness. Scopolamine was the first drug to be made commercially available in a transdermal therapeutic system (TTS-patch) delivering alkaloid. Recently, pharmacokinetic data on scopolamine in different biozlogic matrices were obtained most efficiently using liquid chromatographic-tandem mass spectrometric (LC-MS/MS) or gas chromatography online coupled to mass spectrometry. Pharmacokinetic parameters are dependent on the dosage form (oral dose, tablets; parenteral application; IV infusion; SC and IM injection). Scopolamine has a limited bioavailability if orally administered. The maximum drug concentration occurs approximately 0.5 hours after oral administration. Because only 2.6% of nonmetabolized L-(-)-scopolamine is excreted in urine, a first-pass metabolism is suggested to occur after oral administration of scopolamine. Because of its short half-life in plasma and dose-dependent adverse effects (in particular hallucinations and the less serious reactions, eg, vertigo, dry mouth, drowsiness), the clinical use of scopolamine administered orally or parenterally is limited. To minimize the relatively high incidence of side effects, the transdermal dosage form has been developed. The commercially available TTS-patch contains a 1.5-mg drug reservoir and a priming dose (140 microg) to reach the steady-state concentration of scopolamine quickly. The patch releases 0.5 mg alkaloid over a period of 3 days (releasing rate 5 microg/h). Following the transdermal application of scopolamine, the plasma concentrations of the drug indicate major interindividual variations. Peak plasma concentrations (Cmax) of approximately 100 pg/mL (range 11-240 pg/mL) of the alkaloid are reached after about 8 hours and achieve steady state. During a period of 72 hours the plaster releases scopolamine, so constantly high plasma levels (concentration range 56-245 pg/mL) are obtained, followed by a plateau of urinary scopolamine excretion. Although scopolamine has been used in clinical practice for many years, data concerning its metabolism and the renal excretion in man are limited. After incubation with beta-glucuronidase and sulfatase, the recovery of scopolamine in human urine increased from 3% to approximately 30% of the drug dose (intravenously administered). According to these results from enzymatic hydrolysis of scopolamine metabolites, the glucuronide conjugation of scopolamine could be the relevant pathway in healthy volunteers. However, scopolamine metabolism in man has not been verified stringently. An elucidation of the chemical structures of the metabolites extracted from human urine is still lacking. Scopolamine has been shown to undergo an oxidative demethylation during incubation with CYP3A (cytochrome P-450 subfamily). To inhibit the CYP3A located in the intestinal mucosa, components of grapefruit juice are very suitable. When scopolamine was administered together with 150 mL grapefruit juice, the alkaloid concentrations continued to increase, resulting in an evident prolongation of tmax (59.5 +/- 25.0 minutes; P < 0.001). The AUC0-24h values of scopolamine were higher during the grapefruit juice period. They reached approximately 142% of the values associated with the control group (P < 0.005). Consequently, the related absolute bioavailabilities (range 6% to 37%) were significantly higher than the corresponding values of the drug orally administered together with water (range 3% to 27%). The effect of the alkaloid on quantitative electroencephalogram (qEEG) and cognitive performance correlated with pharmacokinetics was shown in studies with healthy volunteers. From pharmacokinetic-pharmacodynamic modeling techniques, a direct correlation between serum concentrations of scopolamine and changes in total power in alpha-frequency band (EEG) in healthy volunteers was provided. The alkaloid readily crosses the placenta. Therefore, scopolamine should be administered to pregnant women only under observation. The drug is compatible with nursing and is considered to be nonteratogenic. In conclusion, scopolamine is used for premedication in anesthesia and for the prevention of nausea and vomiting associated with motion sickness. Pharmacokinetics and pharmacodynamics of scopolamine depend on the dosage form. Effects on different cognitive functions have been extensively documented.

Darifenacin in the treatment of overactive bladder.

Darifenacin is a novel muscarinic M(3) selective receptor antagonist developed for the once-daily treatment of overactive bladder, a chronic, debilitating and highly prevalent condition affecting adults of all ages. Preclinical research has confirmed the pharmacological profile of darifenacin as a potent antimuscarinic agent with up to 59-fold higher affinity for M(3) receptors than other muscarinic receptor subtypes and selectivity for the bladder over other tissues expressing these receptors. Extensive research in large, randomized, placebo-controlled trials have demonstrated that darifenacin, at doses of 7.5 and 15 mg once daily (q.d.), is efficacious in the treatment of overactive bladder, improving the core symptoms of urinary urgency, urge incontinence, increased micturition frequency and bladder capacity. In addition, post-hoc analyses have shown that many patients can achieve clinically meaningful continence levels, e.g., > or =90% reduction in incontinence episodes or > or =7 consecutive dry days. These results are supported by significant improvements in quality of life, which have paralleled the overactive bladder symptom reductions. Both fixed and flexible darifenacin dosing regimens produce these beneficial effects, which extend to the more vulnerable population of older patients. Hence, in conjunction with data showing that this agent has a good safety and tolerability profile, these findings indicate that darifenacin may provide an effective alternative pharmacotherapy for the treatment of patients with overactive bladder.

Muscarinic M2 antagonists: anthranilamide derivatives with exceptional selectivity and in vivo activity.

Anthranilamide analogues such as 23 are potent and highly selective muscarinic M2 antagonists that also show good oral bioavailability and in vivo activity.

Scopolamine-induced deficits in a two-trial object recognition task in mice.

The purpose of the present study was to design an object recognition task in mice and characterize the effects of scopolamine in this paradigm. This task consisted of exposing mice for 6 or 10 min to an object in an open field (trial 1) and, after a delay (1-24 h), testing mice for 10 min with the object and a novel object (trial 2). Mice explored the novel object more than the familiar object as the inter-trial delay decreased and/or the duration of trial 1 increased. Administration of scopolamine (0.3, 1 and 3 mg kg-1, s.c.) before trial 1 reduced recognition performance on trial 2 after a 3 h inter-trial delay and induced other behavioural effects, including an increase in locomotor activity on trial 1. Methylscopolamine (1 mg kg-1) had no effect on recognition performance. The present results show that this task is a useful model to test recognition memory in mice and that blocking the central cholinergic system impairs this form of memory.